From 2acd4ef91666fc85bf61799bd1c7651bafd993d8 Mon Sep 17 00:00:00 2001 From: Hardik Pawar Date: Mon, 14 Oct 2024 09:42:29 +0530 Subject: [PATCH] Enhance documentation in `FractionalKnapsack` --- .../greedyalgorithms/FractionalKnapsack.java | 41 ++++++++++++------- 1 file changed, 26 insertions(+), 15 deletions(-) diff --git a/src/main/java/com/thealgorithms/greedyalgorithms/FractionalKnapsack.java b/src/main/java/com/thealgorithms/greedyalgorithms/FractionalKnapsack.java index 082bd9c68b32..9535a7c6190e 100644 --- a/src/main/java/com/thealgorithms/greedyalgorithms/FractionalKnapsack.java +++ b/src/main/java/com/thealgorithms/greedyalgorithms/FractionalKnapsack.java @@ -3,39 +3,50 @@ import java.util.Arrays; import java.util.Comparator; -// Problem Link: https://en.wikipedia.org/wiki/Continuous_knapsack_problem - +/** + * The FractionalKnapsack class provides a method to solve the fractional knapsack problem + * using a greedy algorithm approach. It allows for selecting fractions of items to maximize + * the total value in a knapsack with a given weight capacity. + * + * The problem consists of a set of items, each with a weight and a value, and a knapsack + * that can carry a maximum weight. The goal is to maximize the value of items in the knapsack, + * allowing for the inclusion of fractions of items. + * + * Problem Link: https://en.wikipedia.org/wiki/Continuous_knapsack_problem + */ public final class FractionalKnapsack { private FractionalKnapsack() { } - // Function to perform fractional knapsack + + /** + * Computes the maximum value that can be accommodated in a knapsack of a given capacity. + * + * @param weight an array of integers representing the weights of the items + * @param value an array of integers representing the values of the items + * @param capacity an integer representing the maximum weight capacity of the knapsack + * @return the maximum value that can be obtained by including the items in the knapsack + */ public static int fractionalKnapsack(int[] weight, int[] value, int capacity) { - // Create a 2D array to store item indices and their value-to-weight ratios. double[][] ratio = new double[weight.length][2]; - // Populate the ratio array with item indices and their value-to-weight ratios. for (int i = 0; i < weight.length; i++) { - ratio[i][0] = i; // Assign item index. - ratio[i][1] = value[i] / (double) weight[i]; // Calculate and assign value-to-weight ratio. + ratio[i][0] = i; + ratio[i][1] = value[i] / (double) weight[i]; } - // Sort items by their value-to-weight ratios in descending order. Arrays.sort(ratio, Comparator.comparingDouble(o -> o[1])); - int finalValue = 0; // Variable to store the final knapsack value. - double current = capacity; // Variable to track the remaining capacity of the knapsack. + int finalValue = 0; + double current = capacity; - // Iterate through the sorted items to select items for the knapsack. for (int i = ratio.length - 1; i >= 0; i--) { - int index = (int) ratio[i][0]; // Get the item index. + int index = (int) ratio[i][0]; if (current >= weight[index]) { - // If the entire item can fit in the knapsack, add its value. finalValue += value[index]; current -= weight[index]; } else { - // If only a fraction of the item can fit, add a proportionate value. finalValue += (int) (ratio[i][1] * current); - break; // Stop adding items to the knapsack since it's full. + break; } } return finalValue;