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Improve comments in SumOfSubset.java
(#5514)
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@ -1,9 +1,35 @@
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package com.thealgorithms.dynamicprogramming;
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/**
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* A utility class that contains the Sum of Subset problem solution using
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* recursion.
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*
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* The Sum of Subset problem determines whether a subset of elements from a
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* given array sums up to a specific target value.
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*
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* Wikipedia: https://en.wikipedia.org/wiki/Subset_sum_problem
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*/
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public final class SumOfSubset {
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private SumOfSubset() {
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}
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/**
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* Determines if there exists a subset of elements in the array `arr` that
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* adds up to the given `key` value using recursion.
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*
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* @param arr The array of integers.
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* @param num The index of the current element being considered.
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* @param key The target sum we are trying to achieve.
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* @return true if a subset of `arr` adds up to `key`, false otherwise.
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*
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* This is a recursive solution that checks for two possibilities at
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* each step:
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* 1. Include the current element in the subset and check if the
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* remaining elements can sum up to the remaining target.
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* 2. Exclude the current element and check if the remaining elements
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* can sum up to the target without this element.
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*/
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public static boolean subsetSum(int[] arr, int num, int key) {
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if (key == 0) {
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return true;
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@ -14,7 +40,6 @@ public final class SumOfSubset {
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boolean include = subsetSum(arr, num - 1, key - arr[num]);
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boolean exclude = subsetSum(arr, num - 1, key);
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return include || exclude;
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}
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}
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