背包解决数字组合

import java.util.Scanner;

/**
 * @author Oxygen
 * @date 2018年8月30日
 */
public class Main{
	public static void main(String[] args) {
		Scanner scanner = new Scanner(System.in);
		int N = scanner.nextInt();
		int S = scanner.nextInt();
		int[] data = new int[N];
		for (int i = 0; i < data.length; i++) {
			data[i] = scanner.nextInt();
		}
		int[][] dp = new int[N + 1][S + 1];
		for (int i = 1; i < N + 1; i++) {
			for (int j = 1; j < S + 1; j++) {
				if (j == data[i - 1]) {
					dp[i][j] = 1;
				}
			}
		}
		for (int i = 1; i < N + 1; i++) {
			for (int j = 1; j < S + 1; j++) {
				if (j >= data[i - 1]) {
					dp[i][j] += dp[i - 1][j] + dp[i-1][j - data[i - 1]];
				} else {
					dp[i][j] = dp[i - 1][j];
				}
			}
		}
		System.out.println(dp[N][S]);
	}
}