46 lines
1.3 KiB
Java
46 lines
1.3 KiB
Java
package DynamicProgramming;
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public class SubsetSum {
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/**
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* Driver Code
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*/
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public static void main(String[] args) {
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int[] arr = new int[]{50, 4, 10, 15, 34};
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assert subsetSum(arr, 64); /* 4 + 10 + 15 + 34 = 64 */
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assert subsetSum(arr, 99); /* 50 + 15 + 34 = 99 */
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assert !subsetSum(arr, 5);
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assert !subsetSum(arr, 66);
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}
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/**
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* Test if a set of integers contains a subset that sum to a given integer.
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*
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* @param arr the array contains integers.
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* @param sum target sum of subset.
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* @return {@code true} if subset exists, otherwise {@code false}.
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*/
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private static boolean subsetSum(int[] arr, int sum) {
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int n = arr.length;
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boolean[][] isSum = new boolean[n + 2][sum + 1];
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isSum[n + 1][0] = true;
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for (int i = 1; i <= sum; i++) {
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isSum[n + 1][i] = false;
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}
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for (int i = n; i > 0; i--) {
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isSum[i][0] = true;
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for (int j = 1; j <= arr[i - 1] - 1; j++) {
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if (j <= sum) {
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isSum[i][j] = isSum[i + 1][j];
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}
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}
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for (int j = arr[i - 1]; j <= sum; j++) {
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isSum[i][j] = (isSum[i + 1][j] || isSum[i + 1][j - arr[i - 1]]);
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}
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}
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return isSum[1][sum];
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}
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} |