回溯法解决子集和问题

具体参看：http://blog.csdn.net/foolsong/article/details/16970001

package com.alo.offer;import java.util.Scanner;/** * 使用回溯法解决子集和问题 *  * @author Administrator * */public class SubSetSum {static int sum = 0; static int c = 0; //和的值static int n = 0;static int[] arr;static int[] temp;static int t = 0; //子集和存在那么为1，不存在为0public static void main(String[] args) {Scanner input = new Scanner(System.in);n = input.nextInt();c = input.nextInt();arr = new int[n];temp = new int[n];for (int i = 0; i < arr.length; i++) {arr[i] = input.nextInt();}search(0);input.close();if (t == 0) {System.out.println("No Solution!");}}public static void search(int m) {if (sum == c) {t = 1;for (int i = 0; i < m; i++) {if (temp[i] == 1) {System.out.print(arr[i] + " ");}}System.out.println();return;}if (sum > c || m == n) {return;}if (sum + arr[m] <= c) {sum += arr[m];temp[m] = 1;search(m + 1);temp[m] = 0;sum -= arr[m];}search(m + 1);}}