This Presentation will Use to develop your knowledge and doubts in Knapsack problem. This Slide also include Memory function part. Use this Slides to Develop your knowledge on Knapsack and Memory function
This presentation discusses the knapsack problem and its two main versions: 0/1 and fractional. The 0/1 knapsack problem involves indivisible items that are either fully included or not included, and is solved using dynamic programming. The fractional knapsack problem allows items to be partially included, and is solved using a greedy algorithm. Examples are provided of solving each version using their respective algorithms. The time complexity of these algorithms is also presented. Real-world applications of the knapsack problem include cutting raw materials and selecting investments.
Knapsack problem ==>>
Given some items, pack the knapsack to get
the maximum total value. Each item has some
weight and some value. Total weight that we can
carry is no more than some fixed number W.
So we must consider weights of items as well as
their values.
This document discusses greedy algorithms and dynamic programming techniques for solving optimization problems. It covers the activity selection problem, which can be solved greedily by always selecting the shortest remaining activity. It also discusses the knapsack problem and how the fractional version can be solved greedily while the 0-1 version requires dynamic programming due to its optimal substructure but non-greedy nature. Dynamic programming builds up solutions by combining optimal solutions to overlapping subproblems.
This document discusses the greedy algorithm approach and the knapsack problem. It defines greedy algorithms as choosing locally optimal solutions at each step in hopes of reaching a global optimum. The knapsack problem is described as packing items into a knapsack to maximize total value without exceeding weight capacity. An optimal knapsack algorithm is presented that sorts by value-to-weight ratio and fills highest ratios first. An example applies this to maximize profit of 440 by selecting full quantities of items B and A, and half of item C for a knapsack with capacity of 60.
The document discusses the 0-1 knapsack problem and how it can be solved using dynamic programming. It first defines the 0-1 knapsack problem and provides an example. It then explains how a brute force solution would work in exponential time. Next, it describes how to define the problem as subproblems and derive a recursive formula to solve the subproblems in a bottom-up manner using dynamic programming. This builds up the solutions in a table and solves the problem in polynomial time. Finally, it walks through an example applying the dynamic programming algorithm to a sample problem instance.
Knapsack problem algorithm, greedy algorithmHoneyChintal
The document discusses the knapsack problem and algorithms to solve it. It describes the 0-1 knapsack problem, which does not allow breaking items, and the fractional knapsack problem, which does. It provides an example comparing the two. The document then explains the greedy algorithm approach to solve the fractional knapsack problem by calculating value to weight ratios and filling the knapsack with the highest ratio items first. Pseudocode for the greedy fractional knapsack algorithm is provided along with analysis of its time complexity.
The document presents an overview of fractional and 0/1 knapsack problems. It defines the fractional knapsack problem as choosing items with maximum total benefit but fractional amounts allowed, with total weight at most W. An algorithm is provided that takes the item with highest benefit-to-weight ratio in each step. The 0/1 knapsack problem requires choosing whole items. Solutions like greedy and dynamic programming are discussed. An example illustrates applying dynamic programming to a sample 0/1 knapsack problem.
This presentation discusses the knapsack problem and its two main versions: 0/1 and fractional. The 0/1 knapsack problem involves indivisible items that are either fully included or not included, and is solved using dynamic programming. The fractional knapsack problem allows items to be partially included, and is solved using a greedy algorithm. Examples are provided of solving each version using their respective algorithms. The time complexity of these algorithms is also presented. Real-world applications of the knapsack problem include cutting raw materials and selecting investments.
Knapsack problem ==>>
Given some items, pack the knapsack to get
the maximum total value. Each item has some
weight and some value. Total weight that we can
carry is no more than some fixed number W.
So we must consider weights of items as well as
their values.
This document discusses greedy algorithms and dynamic programming techniques for solving optimization problems. It covers the activity selection problem, which can be solved greedily by always selecting the shortest remaining activity. It also discusses the knapsack problem and how the fractional version can be solved greedily while the 0-1 version requires dynamic programming due to its optimal substructure but non-greedy nature. Dynamic programming builds up solutions by combining optimal solutions to overlapping subproblems.
This document discusses the greedy algorithm approach and the knapsack problem. It defines greedy algorithms as choosing locally optimal solutions at each step in hopes of reaching a global optimum. The knapsack problem is described as packing items into a knapsack to maximize total value without exceeding weight capacity. An optimal knapsack algorithm is presented that sorts by value-to-weight ratio and fills highest ratios first. An example applies this to maximize profit of 440 by selecting full quantities of items B and A, and half of item C for a knapsack with capacity of 60.
The document discusses the 0-1 knapsack problem and how it can be solved using dynamic programming. It first defines the 0-1 knapsack problem and provides an example. It then explains how a brute force solution would work in exponential time. Next, it describes how to define the problem as subproblems and derive a recursive formula to solve the subproblems in a bottom-up manner using dynamic programming. This builds up the solutions in a table and solves the problem in polynomial time. Finally, it walks through an example applying the dynamic programming algorithm to a sample problem instance.
Knapsack problem algorithm, greedy algorithmHoneyChintal
The document discusses the knapsack problem and algorithms to solve it. It describes the 0-1 knapsack problem, which does not allow breaking items, and the fractional knapsack problem, which does. It provides an example comparing the two. The document then explains the greedy algorithm approach to solve the fractional knapsack problem by calculating value to weight ratios and filling the knapsack with the highest ratio items first. Pseudocode for the greedy fractional knapsack algorithm is provided along with analysis of its time complexity.
The document presents an overview of fractional and 0/1 knapsack problems. It defines the fractional knapsack problem as choosing items with maximum total benefit but fractional amounts allowed, with total weight at most W. An algorithm is provided that takes the item with highest benefit-to-weight ratio in each step. The 0/1 knapsack problem requires choosing whole items. Solutions like greedy and dynamic programming are discussed. An example illustrates applying dynamic programming to a sample 0/1 knapsack problem.
The document discusses the knapsack problem and greedy algorithms. It defines the knapsack problem as an optimization problem where given constraints and an objective function, the goal is to find the feasible solution that maximizes or minimizes the objective. It describes the knapsack problem has having two versions: 0-1 where items are indivisible, and fractional where items can be divided. The fractional knapsack problem can be solved using a greedy approach by sorting items by value to weight ratio and filling the knapsack accordingly until full.
Knapsack problem using dynamic programmingkhush_boo31
The document describes the 0-1 knapsack problem and provides an example of solving it using dynamic programming. Specifically, it defines the 0-1 knapsack problem, provides the formula for solving it dynamically using a 2D array C, walks through populating the C array and backtracking to find the optimal solution for a sample problem instance, and analyzes the time complexity of the dynamic programming algorithm.
The document discusses the 0/1 knapsack problem and dynamic programming algorithm to solve it. The 0/1 knapsack problem involves selecting a subset of items to pack in a knapsack that maximizes the total value without exceeding the knapsack's weight capacity. The dynamic programming algorithm solves this by building up a table where each entry represents the maximum value for a given weight. It iterates through items, checking if including each item increases the maximum value for that weight.
Given weights and values of n items, put these items in a knapsack of capacity W to get the maximum total value in the knapsack. In other words, given two integer arrays val[0..n-1] and wt[0..n-1] which represent values and weights associated with n items respectively. Also given an integer W which represents knapsack capacity, find out the maximum value subset of val[] such that sum of the weights of this subset is smaller than or equal to W. You cannot break an item, either pick the complete item or don’t pick it (0-1 property).
Method 1: Recursion by Brute-Force algorithm OR Exhaustive Search.
Approach: A simple solution is to consider all subsets of items and calculate the total weight and value of all subsets. Consider the only subsets whose total weight is smaller than W. From all such subsets, pick the maximum value subset.
Optimal Sub-structure: To consider all subsets of items, there can be two cases for every item.
Case 1: The item is included in the optimal subset.
Case 2: The item is not included in the optimal set.
Therefore, the maximum value that can be obtained from ‘n’ items is the max of the following two values.
Maximum value obtained by n-1 items and W weight (excluding nth item).
Value of nth item plus maximum value obtained by n-1 items and W minus the weight of the nth item (including nth item).
If the weight of the ‘nth’ item is greater than ‘W’, then the nth item cannot be included and Case 1 is the only possibility.
This is a short presentation on Vertex Cover Problem for beginners in the field of Graph Theory...
Download the presentation for a better experience...
This document discusses optimal binary search trees and provides an example problem. It begins with basic definitions of binary search trees and optimal binary search trees. It then shows an example problem with keys 1, 2, 3 and calculates the cost as 17. The document explains how to use dynamic programming to find the optimal binary search tree for keys 10, 12, 16, 21 with frequencies 4, 2, 6, 3. It provides the solution matrix and explains that the minimum cost is 2 with the optimal tree as 10, 12, 16, 21.
The document discusses various backtracking techniques including bounding functions, promising functions, and pruning to avoid exploring unnecessary paths. It provides examples of problems that can be solved using backtracking including n-queens, graph coloring, Hamiltonian circuits, sum-of-subsets, 0-1 knapsack. Search techniques for backtracking problems include depth-first search (DFS), breadth-first search (BFS), and best-first search combined with branch-and-bound pruning.
The document discusses two types of knapsack problems - the 0-1 knapsack problem and the fractional knapsack problem. The 0-1 knapsack problem uses dynamic programming to determine how to fill a knapsack to maximize the total value of items without exceeding the knapsack's weight limit, where each item is either fully included or not included. The fractional knapsack problem allows partial inclusion of items and can be solved greedily by always including a fraction of the highest value per unit weight item until the knapsack is full.
The 0-1 knapsack problem involves selecting items with given values and weights to maximize the total value without exceeding a weight capacity. It can be solved using a brute force approach in O(2^n) time or dynamic programming in O(n*c) time. Dynamic programming constructs a value matrix where each cell represents the maximum value for a given item and weight. The cell value is either from the item above or adding the item's value if the weight is less than remaining capacity. The last cell provides the maximum value solution.
The branch-and-bound method is used to solve optimization problems by traversing a state space tree. It computes a bound at each node to determine if the node is promising. Better approaches traverse nodes breadth-first and choose the most promising node using a bounding heuristic. The traveling salesperson problem is solved using branch-and-bound by finding an initial tour, defining a bounding heuristic as the actual cost plus minimum remaining cost, and expanding promising nodes in best-first order until finding the minimal tour.
Analysis & Design of Algorithms
Backtracking
N-Queens Problem
Hamiltonian circuit
Graph coloring
A presentation on unit Backtracking from the ADA subject of Engineering.
The Bellman–Ford algorithm is an algorithm that computes shortest paths from a single source vertex to all of the other vertices in a weighted digraph.
The document discusses the knapsack problem, which involves selecting a subset of items that fit within a knapsack of limited capacity to maximize the total value. There are two versions - the 0-1 knapsack problem where items can only be selected entirely or not at all, and the fractional knapsack problem where items can be partially selected. Solutions include brute force, greedy algorithms, and dynamic programming. Dynamic programming builds up the optimal solution by considering all sub-problems.
The document discusses the greedy method algorithmic approach. It provides an overview of greedy algorithms including that they make locally optimal choices at each step to find a global optimal solution. The document also provides examples of problems that can be solved using greedy methods like job sequencing, the knapsack problem, finding minimum spanning trees, and single source shortest paths. It summarizes control flow and applications of greedy algorithms.
The document discusses the 0/1 knapsack problem and the greedy algorithm approach. It describes the knapsack problem as selecting a subset of items with weights and values that fit within a knapsack capacity while maximizing the total value. The greedy algorithm works by selecting the highest value item at each step that fits within remaining capacity. The document provides an example problem of selecting boxes to fill a knapsack of 15kg capacity to maximize profit. It outlines the recurrence relation and time/space complexity of the greedy knapsack algorithm.
This document discusses various problems that can be solved using backtracking, including graph coloring, the Hamiltonian cycle problem, the subset sum problem, the n-queen problem, and map coloring. It provides examples of how backtracking works by constructing partial solutions and evaluating them to find valid solutions or determine dead ends. Key terms like state-space trees and promising vs non-promising states are introduced. Specific examples are given for problems like placing 4 queens on a chessboard and coloring a map of Australia.
This document discusses NP-complete problems and their properties. Some key points:
- NP-complete problems have an exponential upper bound on runtime but only a polynomial lower bound, making them appear intractable. However, their intractability cannot be proven.
- NP-complete problems are reducible to each other in polynomial time. Solving one would solve all NP-complete problems.
- NP refers to problems that can be verified in polynomial time. P refers to problems that can be solved in polynomial time.
- A problem is NP-complete if it is in NP and all other NP problems can be reduced to it in polynomial time. Proving a problem is NP-complete involves showing
The document discusses the 0-1 knapsack problem and provides an example of solving it using dynamic programming. The 0-1 knapsack problem aims to maximize the total value of items selected from a list that have a total weight less than or equal to the knapsack's capacity, where each item must either be fully included or excluded. The document outlines a dynamic programming algorithm that builds a table to store the maximum value for each item subset at each possible weight, recursively considering whether or not to include each additional item.
This document discusses dynamic programming and its application to solve the knapsack problem.
It begins by defining dynamic programming as a technique for solving problems with overlapping subproblems where each subproblem is solved only once and the results are stored in a table.
It then defines the knapsack problem as selecting a subset of items with weights and values that fit in a knapsack of capacity W to maximize the total value.
The document shows how to solve the knapsack problem using dynamic programming by constructing a table where each entry table[i,j] represents the maximum value for items 1 to i with weight ≤ j. It provides an example problem and walks through filling the table and backtracking to find
The document discusses the knapsack problem and greedy algorithms. It defines the knapsack problem as an optimization problem where given constraints and an objective function, the goal is to find the feasible solution that maximizes or minimizes the objective. It describes the knapsack problem has having two versions: 0-1 where items are indivisible, and fractional where items can be divided. The fractional knapsack problem can be solved using a greedy approach by sorting items by value to weight ratio and filling the knapsack accordingly until full.
Knapsack problem using dynamic programmingkhush_boo31
The document describes the 0-1 knapsack problem and provides an example of solving it using dynamic programming. Specifically, it defines the 0-1 knapsack problem, provides the formula for solving it dynamically using a 2D array C, walks through populating the C array and backtracking to find the optimal solution for a sample problem instance, and analyzes the time complexity of the dynamic programming algorithm.
The document discusses the 0/1 knapsack problem and dynamic programming algorithm to solve it. The 0/1 knapsack problem involves selecting a subset of items to pack in a knapsack that maximizes the total value without exceeding the knapsack's weight capacity. The dynamic programming algorithm solves this by building up a table where each entry represents the maximum value for a given weight. It iterates through items, checking if including each item increases the maximum value for that weight.
Given weights and values of n items, put these items in a knapsack of capacity W to get the maximum total value in the knapsack. In other words, given two integer arrays val[0..n-1] and wt[0..n-1] which represent values and weights associated with n items respectively. Also given an integer W which represents knapsack capacity, find out the maximum value subset of val[] such that sum of the weights of this subset is smaller than or equal to W. You cannot break an item, either pick the complete item or don’t pick it (0-1 property).
Method 1: Recursion by Brute-Force algorithm OR Exhaustive Search.
Approach: A simple solution is to consider all subsets of items and calculate the total weight and value of all subsets. Consider the only subsets whose total weight is smaller than W. From all such subsets, pick the maximum value subset.
Optimal Sub-structure: To consider all subsets of items, there can be two cases for every item.
Case 1: The item is included in the optimal subset.
Case 2: The item is not included in the optimal set.
Therefore, the maximum value that can be obtained from ‘n’ items is the max of the following two values.
Maximum value obtained by n-1 items and W weight (excluding nth item).
Value of nth item plus maximum value obtained by n-1 items and W minus the weight of the nth item (including nth item).
If the weight of the ‘nth’ item is greater than ‘W’, then the nth item cannot be included and Case 1 is the only possibility.
This is a short presentation on Vertex Cover Problem for beginners in the field of Graph Theory...
Download the presentation for a better experience...
This document discusses optimal binary search trees and provides an example problem. It begins with basic definitions of binary search trees and optimal binary search trees. It then shows an example problem with keys 1, 2, 3 and calculates the cost as 17. The document explains how to use dynamic programming to find the optimal binary search tree for keys 10, 12, 16, 21 with frequencies 4, 2, 6, 3. It provides the solution matrix and explains that the minimum cost is 2 with the optimal tree as 10, 12, 16, 21.
The document discusses various backtracking techniques including bounding functions, promising functions, and pruning to avoid exploring unnecessary paths. It provides examples of problems that can be solved using backtracking including n-queens, graph coloring, Hamiltonian circuits, sum-of-subsets, 0-1 knapsack. Search techniques for backtracking problems include depth-first search (DFS), breadth-first search (BFS), and best-first search combined with branch-and-bound pruning.
The document discusses two types of knapsack problems - the 0-1 knapsack problem and the fractional knapsack problem. The 0-1 knapsack problem uses dynamic programming to determine how to fill a knapsack to maximize the total value of items without exceeding the knapsack's weight limit, where each item is either fully included or not included. The fractional knapsack problem allows partial inclusion of items and can be solved greedily by always including a fraction of the highest value per unit weight item until the knapsack is full.
The 0-1 knapsack problem involves selecting items with given values and weights to maximize the total value without exceeding a weight capacity. It can be solved using a brute force approach in O(2^n) time or dynamic programming in O(n*c) time. Dynamic programming constructs a value matrix where each cell represents the maximum value for a given item and weight. The cell value is either from the item above or adding the item's value if the weight is less than remaining capacity. The last cell provides the maximum value solution.
The branch-and-bound method is used to solve optimization problems by traversing a state space tree. It computes a bound at each node to determine if the node is promising. Better approaches traverse nodes breadth-first and choose the most promising node using a bounding heuristic. The traveling salesperson problem is solved using branch-and-bound by finding an initial tour, defining a bounding heuristic as the actual cost plus minimum remaining cost, and expanding promising nodes in best-first order until finding the minimal tour.
Analysis & Design of Algorithms
Backtracking
N-Queens Problem
Hamiltonian circuit
Graph coloring
A presentation on unit Backtracking from the ADA subject of Engineering.
The Bellman–Ford algorithm is an algorithm that computes shortest paths from a single source vertex to all of the other vertices in a weighted digraph.
The document discusses the knapsack problem, which involves selecting a subset of items that fit within a knapsack of limited capacity to maximize the total value. There are two versions - the 0-1 knapsack problem where items can only be selected entirely or not at all, and the fractional knapsack problem where items can be partially selected. Solutions include brute force, greedy algorithms, and dynamic programming. Dynamic programming builds up the optimal solution by considering all sub-problems.
The document discusses the greedy method algorithmic approach. It provides an overview of greedy algorithms including that they make locally optimal choices at each step to find a global optimal solution. The document also provides examples of problems that can be solved using greedy methods like job sequencing, the knapsack problem, finding minimum spanning trees, and single source shortest paths. It summarizes control flow and applications of greedy algorithms.
The document discusses the 0/1 knapsack problem and the greedy algorithm approach. It describes the knapsack problem as selecting a subset of items with weights and values that fit within a knapsack capacity while maximizing the total value. The greedy algorithm works by selecting the highest value item at each step that fits within remaining capacity. The document provides an example problem of selecting boxes to fill a knapsack of 15kg capacity to maximize profit. It outlines the recurrence relation and time/space complexity of the greedy knapsack algorithm.
This document discusses various problems that can be solved using backtracking, including graph coloring, the Hamiltonian cycle problem, the subset sum problem, the n-queen problem, and map coloring. It provides examples of how backtracking works by constructing partial solutions and evaluating them to find valid solutions or determine dead ends. Key terms like state-space trees and promising vs non-promising states are introduced. Specific examples are given for problems like placing 4 queens on a chessboard and coloring a map of Australia.
This document discusses NP-complete problems and their properties. Some key points:
- NP-complete problems have an exponential upper bound on runtime but only a polynomial lower bound, making them appear intractable. However, their intractability cannot be proven.
- NP-complete problems are reducible to each other in polynomial time. Solving one would solve all NP-complete problems.
- NP refers to problems that can be verified in polynomial time. P refers to problems that can be solved in polynomial time.
- A problem is NP-complete if it is in NP and all other NP problems can be reduced to it in polynomial time. Proving a problem is NP-complete involves showing
The document discusses the 0-1 knapsack problem and provides an example of solving it using dynamic programming. The 0-1 knapsack problem aims to maximize the total value of items selected from a list that have a total weight less than or equal to the knapsack's capacity, where each item must either be fully included or excluded. The document outlines a dynamic programming algorithm that builds a table to store the maximum value for each item subset at each possible weight, recursively considering whether or not to include each additional item.
This document discusses dynamic programming and its application to solve the knapsack problem.
It begins by defining dynamic programming as a technique for solving problems with overlapping subproblems where each subproblem is solved only once and the results are stored in a table.
It then defines the knapsack problem as selecting a subset of items with weights and values that fit in a knapsack of capacity W to maximize the total value.
The document shows how to solve the knapsack problem using dynamic programming by constructing a table where each entry table[i,j] represents the maximum value for items 1 to i with weight ≤ j. It provides an example problem and walks through filling the table and backtracking to find
The document describes the 0-1 knapsack problem and how to solve it using dynamic programming. The 0-1 knapsack problem involves packing items of different weights and values into a knapsack of maximum capacity to maximize the total value without exceeding the weight limit. A dynamic programming algorithm is presented that breaks the problem down into subproblems and uses optimal substructure and overlapping subproblems to arrive at the optimal solution in O(nW) time, improving on the brute force O(2^n) time. An example is shown step-by-step to illustrate the algorithm.
Design and analysis of Algorithms - Lecture 15.pptQurbanAli72
The document describes the 0/1 knapsack problem, which involves selecting a subset of items to pack in a knapsack without exceeding the knapsack's weight limit, in order to maximize the total value of the items. It presents a dynamic programming algorithm that solves the problem in polynomial time by building up the optimal solution for subproblems. The algorithm fills a two-dimensional table where each entry represents the maximum value achievable for a given subset of items with a particular remaining weight capacity.
0 1 knapsack using naive recursive approach and top-down dynamic programming ...Abhishek Singh
This slide contains 0-1 knapsack problem using naive recursive approach and using top-down dynamic programming approach. Here we have used memorization to optimize the recursive approach.
The document describes the 0-1 knapsack problem and provides an example of solving it using dynamic programming. The 0-1 knapsack problem involves packing items into a knapsack of maximum capacity W to maximize the total value of packed items, where each item has a weight and value. The document defines the problem as a recursive subproblem and provides pseudocode for a dynamic programming algorithm that runs in O(nW) time, improving on the brute force O(2^n) time. It then works through an example application of the algorithm to a sample problem with 4 items and knapsack capacity of 5.
Dynamic programming is a technique for solving problems with overlapping subproblems by breaking them down into smaller subproblems and storing the results of already solved subproblems in a table to build up the solution. It was developed in the 1950s and involves setting up recurrences relating solutions to larger instances to smaller instances and solving the smaller instances once to extract the solution. Examples given include computing the nth Fibonacci number and solving the knapsack problem by filling a table and using solutions to smaller capacities and numbers of items.
The document discusses different types of knapsack problems. It provides an example of a 0/1 knapsack problem where items must either be fully included or excluded from a knapsack with limited capacity. Brute force and greedy algorithms are presented as approaches to solve such problems. The document also briefly introduces fractional knapsack problems and provides pseudocode for a greedy algorithm solution.
The document discusses the 0-1 knapsack problem and presents a dynamic programming algorithm to solve it. The 0-1 knapsack problem aims to maximize the total value of items selected without exceeding the knapsack's weight capacity, where each item must either be fully included or excluded. The algorithm uses a table B to store the maximum value for each sub-problem of filling weight w with the first i items, calculating entries recursively to find the overall optimal value B[n,W]. An example demonstrates filling the table to solve an instance of the problem.
The document discusses greedy algorithms and how they work. It provides an example of using a greedy algorithm to solve the fractional knapsack problem in 3 steps: (1) sorting items by value to weight ratio, (2) initializing a selection array, (3) iteratively selecting highest ratio items that fit in the knapsack until full. While fast, greedy algorithms may not always find the optimal solution. The document also covers using Huffman coding to create efficient variable-length codes.
This document discusses inner product spaces and properties of the inner product. It provides examples of determining the inner product of vectors and applying properties like commutativity, distributivity, and associativity. It also defines length in Rn and discusses the Euclidean plane E2, defining distance between points as the absolute value of their difference. Students will learn to determine if a function defines an inner product, find inner products of vectors, and solve for distances in E2.
Dynamic programming can be used to solve optimization problems involving overlapping subproblems, such as finding the most valuable subset of items that fit in a knapsack. The knapsack problem is solved by considering all possible subsets incrementally, storing the optimal values in a table. Warshall's and Floyd's algorithms also use dynamic programming to find the transitive closure and shortest paths in graphs by iteratively building up the solution from smaller subsets. Optimal binary search trees can also be constructed using dynamic programming by considering optimal substructures.
This paper analyze few algorithms of the 0/1 Knapsack Problem and fractional
knapsack problem. This problem is a combinatorial optimization problem in which one has
to maximize the benefit of objects without exceeding capacity. As it is an NP-complete
problem, an exact solution for a large input is not possible. Hence, paper presents a
comparative study of the Greedy and dynamic methods. It also gives complexity of each
algorithm with respect to time and space requirements. Our experimental results show that
the most promising approaches are dynamic programming.
Dynamic Programming is a method for solving a complex problem by breaking it down into a collection of simpler subproblems, solving each of those subproblems just once, and storing their solutions using a memory-based data structure (array, map,etc).
The document discusses greedy algorithms and provides examples of how they can be applied to solve optimization problems like the knapsack problem. It defines greedy techniques as making locally optimal choices at each step to arrive at a global solution. Examples where greedy algorithms are used include finding the shortest path, minimum spanning tree (using Prim's and Kruskal's algorithms), job sequencing with deadlines, and the fractional knapsack problem. Pseudocode and examples are provided to demonstrate how greedy algorithms work for the knapsack problem and job sequencing problem.
Given two integer arrays val[0...n-1] and wt[0...n-1] that represents values and weights associated with n items respectively. Find out the maximum value subset of val[] such that sum of the weights of this subset is smaller than or equal to knapsack capacity W. Here the BRANCH AND BOUND ALGORITHM is discussed .
The document describes the 0/1 knapsack problem and an algorithm to solve it using branch and bound. Specifically, it discusses:
- The knapsack problem involves finding the maximum value subset of items whose total weight is less than or equal to the knapsack capacity, given item values and weights.
- Branch and bound is used because greedy approaches do not work if weights are not fractional and brute force has exponential time complexity.
- The algorithm sorts items by value/weight ratio, initializes variables, and uses a queue to iteratively explore branches, pruning branches that cannot improve the best solution found so far.
This document discusses dynamic programming and provides examples of how it can be applied to optimize algorithms to solve problems with overlapping subproblems. It summarizes dynamic programming, provides examples for the Fibonacci numbers, binomial coefficients, and knapsack problems, and analyzes the time and space complexity of algorithms developed using dynamic programming approaches.
Similar to Knapsack problem and Memory Function (20)
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This document proposes a remote monitoring system for ECG signals using cloud computing and wireless networks. The system allows ECG signals from patients to be monitored simultaneously by experts. If an abnormality is detected, a message is sent to the cloud and doctor. This could help reduce delays in treatment for heart patients and lower mortality rates. The system uses electrocardiogram signals sent via ZigBee to the cloud where doctors can access the data remotely. This provides availability and reliability of critical patient data through cloud-based storage and access.
This Presentation will use to develop your knowledge in Fourier Transform mostly in Application side. So Kindly Use this presentation to enrich your knowledge in Fourier transform Domain and if any queries mail me baranitharan2020@gmail.com I'll solve your Doubts
The document provides the name M. Baranitharan and indicates they are associated with Kings College of Engineering. No other details are provided about the person or organization in the short text.
Covid Management System Project Report.pdfKamal Acharya
CoVID-19 sprang up in Wuhan China in November 2019 and was declared a pandemic by the in January 2020 World Health Organization (WHO). Like the Spanish flu of 1918 that claimed millions of lives, the COVID-19 has caused the demise of thousands with China, Italy, Spain, USA and India having the highest statistics on infection and mortality rates. Regardless of existing sophisticated technologies and medical science, the spread has continued to surge high. With this COVID-19 Management System, organizations can respond virtually to the COVID-19 pandemic and protect, educate and care for citizens in the community in a quick and effective manner. This comprehensive solution not only helps in containing the virus but also proactively empowers both citizens and care providers to minimize the spread of the virus through targeted strategies and education.
This is an overview of my current metallic design and engineering knowledge base built up over my professional career and two MSc degrees : - MSc in Advanced Manufacturing Technology University of Portsmouth graduated 1st May 1998, and MSc in Aircraft Engineering Cranfield University graduated 8th June 2007.
Online train ticket booking system project.pdfKamal Acharya
Rail transport is one of the important modes of transport in India. Now a days we
see that there are railways that are present for the long as well as short distance
travelling which makes the life of the people easier. When compared to other
means of transport, a railway is the cheapest means of transport. The maintenance
of the railway database also plays a major role in the smooth running of this
system. The Online Train Ticket Management System will help in reserving the
tickets of the railways to travel from a particular source to the destination.
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Knapsack problem and Memory Function
1. KNAPSACK PROBLEM AND MEMORY
FUNCTION
PREPARED BY
M. Baranitharan
Kings College of Engineering
2. Given some items, pack the knapsack to get
the maximum total value. Each item has some
weight and some value. Total weight that we can
carry is no more than some fixed number W.
So we must consider weights of items as well as
their values.
Item # Weight Value
1 1 8
2 3 6
3 5 5
3. There are two versions of the problem:
1. “0-1 knapsack problem”
Items are indivisible; you either take an item or not.
Some special instances can be solved with dynamic
programming
1. “Fractional knapsack problem”
Items are divisible: you can take any fraction of an
item
4. Given a knapsack with maximum capacity W, and
a set S consisting of n items
Each item i has some weight wi and benefit value
bi (all wi and W are integer values)
Problem: How to pack the knapsack to achieve
maximum total value of packed items?
5. Problem, in other words, is to find
∑∑ ∈∈
≤
Ti
i
Ti
i Wwb subject tomax
The problem is called a “0-1” problem,
because each item must be entirely
accepted or rejected.
6. Let’s first solve this problem with a
straightforward algorithm
Since there are n items, there are 2n
possible
combinations of items.
We go through all combinations and find the
one with maximum value and with total weight
less or equal to W
Running time will be O(2n
)
7. We can do better with an algorithm based on
dynamic programming
We need to carefully identify the subproblems
8. Given a knapsack with maximum capacity W, and
a set S consisting of n items
Each item i has some weight wi and benefit value
bi (all wi and W are integer values)
Problem: How to pack the knapsack to achieve
maximum total value of packed items?
9. We can do better with an algorithm based on
dynamic programming
We need to carefully identify the subproblems
Let’s try this:
If items are labeled 1..n, then a subproblem
would be to find an optimal solution for
Sk = {items labeled 1, 2, .. k}
10. If items are labeled 1..n, then a subproblem
would be to find an optimal solution for Sk =
{items labeled 1, 2, .. k}
This is a reasonable subproblem definition.
The question is: can we describe the final
solution (Sn ) in terms of subproblems (Sk)?
Unfortunately, we can’t do that.
11. Max weight: W = 20
For S4:
Total weight: 14
Maximum benefit: 20
w1 =2
b1 =3
w2 =4
b2 =5
w3 =5
b3 =8
w4 =3
b4 =4 wi bi
10
85
54
43
32
Weight Benefit
9
Item
#
4
3
2
1
5
S4
S5
w1 =2
b1 =3
w2 =4
b2 =5
w3 =5
b3 =8
w5 =9
b5 =10
For S5:
Total weight: 20
Maximum benefit: 26
Solution for S4 is
not part of the
solution for S !!!
?
12. As we have seen, the solution for S4 is not part of
the solution for S5
So our definition of a subproblem is flawed and we
need another one!
13. Given a knapsack with maximum capacity W, and
a set S consisting of n items
Each item i has some weight wi and benefit value
bi (all wi and W are integer values)
Problem: How to pack the knapsack to achieve
maximum total value of packed items?
14. Let’s add another parameter: w, which will
represent the maximum weight for each subset of
items
The subproblem then will be to compute V[k,w],
i.e., to find an optimal solution for Sk = {items
labeled 1, 2, .. k} in a knapsack of size w
15. The subproblem will then be to compute V[k,w],
i.e., to find an optimal solution for Sk = {items
labeled 1, 2, .. k} in a knapsack of size w
Assuming knowing V[i, j], where i=0,1, 2, … k-1,
j=0,1,2, …w, how to derive V[k,w]?
16. It means, that the best subset of Sk that has total
weight w is:
1) the best subset of Sk-1 that has total weight ≤ w, or
2) the best subset of Sk-1 that has total weight ≤ w-wk plus
the item k
+−−−
>−
=
else}],1[],,1[max{
if],1[
],[
kk
k
bwwkVwkV
wwwkV
wkV
Recursive formula for subproblems:
17. The best subset of Sk that has the total weight ≤ w,
either contains item k or not.
First case: wk>w. Item k can’t be part of the solution,
since if it was, the total weight would be > w, which is
unacceptable.
Second case: wk ≤ w. Then the item k can be in the
solution, and we choose the case with greater value.
+−−−
>−
=
else}],1[],,1[max{
if],1[
],[
kk
k
bwwkVwkV
wwwkV
wkV
18. for w = 0 to W
V[0,w] = 0
for i = 1 to n
V[i,0] = 0
for i = 1 to n
for w = 0 to W
if wi <= w // item i can be part of the solution
if bi + V[i-1,w-wi] > V[i-1,w]
V[i,w] = bi + V[i-1,w- wi]
else
V[i,w] = V[i-1,w]
else V[i,w] = V[i-1,w] // wi > w
19. for w = 0 to W
V[0,w] = 0
for i = 1 to n
V[i,0] = 0
for i = 1 to n
for w = 0 to W
< the rest of the code >
What is the running time of this
algorithm?
O(W)
O(W)
Repeat n times
O(n*W)
Remember that the brute-force algorithm
takes O(2n
)
20. Let’s run our algorithm on the
following data:
n = 4 (# of elements)
W = 5 (max weight)
Elements (weight, benefit):
(2,3), (3,4), (4,5), (5,6)
21. for w = 0 to W
V[0,w] = 0
0 0 0 0 000
1
2
3
4 50 1 2 3
4
iW
22. for i = 1 to n
V[i,0] = 0
0
0
0
0
0 0 0 0 000
1
2
3
4 50 1 2 3
4
iW
23. if wi <= w // item i can be part of the solution
if bi + V[i-1,w-wi] > V[i-1,w]
V[i,w] = bi + V[i-1,w- wi]
else
V[i,w] = V[i-1,w]
else V[i,w] = V[i-1,w] // wi > w
0
Items:
1: (2,3)
2: (3,4)
3: (4,5)
4: (5,6)
0
i=1
bi=3
wi=2
w=1
w-wi =-1
0 0 0 0 000
1
2
3
4 50 1 2 3
4
iW
0
0
0
24. Items:
1: (2,3)
2: (3,4)
3: (4,5)
4: (5,6)
300
0
0
0
0 0 0 0 000
1
2
3
4 50 1 2 3
4
iW
i=1
bi=3
wi=2
w=4
w-wi =2
if wi <= w // item i can be part of the solution
if bi + V[i-1,w-wi] > V[i-1,w]
V[i,w] = bi + V[i-1,w- wi]
else
V[i,w] = V[i-1,w]
else V[i,w] = V[i-1,w] // wi > w
3 3
25. Items:
1: (2,3)
2: (3,4)
3: (4,5)
4: (5,6)
300
0
0
0
0 0 0 0 000
1
2
3
4 50 1 2 3
4
iW
i=1
bi=3
wi=2
w=5
w-wi =3
if wi <= w // item i can be part of the solution
if bi + V[i-1,w-wi] > V[i-1,w]
V[i,w] = bi + V[i-1,w- wi]
else
V[i,w] = V[i-1,w]
else V[i,w] = V[i-1,w] // wi > w
3 3 3
26. Items:
1: (2,3)
2: (3,4)
3: (4,5)
4: (5,6)
00
0
0
0
0 0 0 0 000
1
2
3
4 50 1 2 3
4
iW
i=2
bi=4
wi=3
w=2
w-wi =-1
3 3 3 3
3
if wi <= w // item i can be part of the solution
if bi + V[i-1,w-wi] > V[i-1,w]
V[i,w] = bi + V[i-1,w- wi]
else
V[i,w] = V[i-1,w]
else V[i,w] = V[i-1,w] // wi > w
0
27. Items:
1: (2,3)
2: (3,4)
3: (4,5)
4: (5,6)
00
0
0
0
0 0 0 0 000
1
2
3
4 50 1 2 3
4
iW
i=2
bi=4
wi=3
w=3
w-wi =0
3 3 3 3
0
if wi <= w // item i can be part of the solution
if bi + V[i-1,w-wi] > V[i-1,w]
V[i,w] = bi + V[i-1,w- wi]
else
V[i,w] = V[i-1,w]
else V[i,w] = V[i-1,w] // wi > w
43
28. Items:
1: (2,3)
2: (3,4)
3: (4,5)
4: (5,6)
00
0
0
0
0 0 0 0 000
1
2
3
4 50 1 2 3
4
iW
i=3
bi=5
wi=4
w= 1..3
3 3 3 3
0 3 4 4
if wi <= w // item i can be part of the solution
if bi + V[i-1,w-wi] > V[i-1,w]
V[i,w] = bi + V[i-1,w- wi]
else
V[i,w] = V[i-1,w]
else V[i,w] = V[i-1,w] // wi > w
7
3 40
29. Items:
1: (2,3)
2: (3,4)
3: (4,5)
4: (5,6)
00
0
0
0
0 0 0 0 000
1
2
3
4 50 1 2 3
4
iW
i=4
bi=6
wi=5
w= 1..4
3 3 3 3
0 3 4 4
if wi <= w // item i can be part of the solution
if bi + V[i-1,w-wi] > V[i-1,w]
V[i,w] = bi + V[i-1,w- wi]
else
V[i,w] = V[i-1,w]
else V[i,w] = V[i-1,w] // wi > w
7
3 40
70 3 4 5
5
30. Items:
1: (2,3)
2: (3,4)
3: (4,5)
4: (5,6)
00
0
0
0
0 0 0 0 000
1
2
3
4 50 1 2 3
4
iW
i=4
bi=6
wi=5
w= 5
w- wi=0
3 3 3 3
0 3 4 4 7
0 3 4
if wi <= w // item i can be part of the solution
if bi + V[i-1,w-wi] > V[i-1,w]
V[i,w] = bi + V[i-1,w- wi]
else
V[i,w] = V[i-1,w]
else V[i,w] = V[i-1,w] // wi > w
5
7
7
0 3 4 5
31. This algorithm only finds the max possible value
that can be carried in the knapsack
◦ i.e., the value in V[n,W]
To know the items that make this maximum value,
an addition to this algorithm is necessary
32. All of the information we need is in the table.
V[n,W] is the maximal value of items that can be
placed in the Knapsack.
Let i=n and k=W
if V[i,k] ≠ V[i−1,k] then
mark the ith
item as in the knapsack
i = i−1, k = k-wi
else
i = i−1 // Assume the ith
item is not in the knapsack
// Could it be in the optimally packed
knapsack?
33. Goal:
◦ Solve only subproblems that are necessary and solve it only once
Memorization is another way to deal with overlapping subproblems
in dynamic programming
With memorization, we implement the algorithm recursively:
◦ If we encounter a new subproblem, we compute and store the solution.
◦ If we encounter a subproblem we have seen, we look up the answer
Most useful when the algorithm is easiest to implement recursively
◦ Especially if we do not need solutions to all subproblems.
34. for i = 1 to n
for w = 1 to W
V[i,w] = -1
for w = 0 to W
V[0,w] = 0
for i = 1 to n
V[i,0] = 0
MFKnapsack(i, w)
if V[i,w] < 0
if w < wi
value = MFKnapsack(i-1, w)
else
value = max(MFKnapsack(i-1, w),
bi + MFKnapsack(i-1, w-wi))
V[i,w] = value
return V[i,w]
35. Dynamic programming is a useful technique of
solving certain kind of problems
When the solution can be recursively described
in terms of partial solutions, we can store these
partial solutions and re-use them as necessary
(memorization)
Running time of dynamic programming
algorithm vs. naïve algorithm:
◦ 0-1 Knapsack problem: O(W*n) vs. O(2n
)