洛谷 P1460 健康的荷斯坦奶牛 —— Java（DFS）

import java.util.Scanner;

public class Main{
	static int[] need = new int[26];
	static int[][] flood = new int[16][26];
	static int n,m;
	static boolean[] vis = new boolean[30];
	static int sum = 0;
	static int[] d = new int[30];
	static int min = Integer.MAX_VALUE;
	static int[] ans = new int[30];
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		n = sc.nextInt();
		for (int i = 0; i < n; i++) {
			need[i] = sc.nextInt();
		}
		m = sc.nextInt();
		for (int i = 0; i < m; i++) {
			for (int j = 0; j < n; j++) {
				flood[i][j] = sc.nextInt();
			}
		}
		dfs(0,0);
		System.out.print(min + " ");
		for (int i = 0; i < min; i++) {
			System.out.print(ans[i]+1 + " ");
		}
	}
	public static void dfs(int step,int choose) {
		if (step == m) {
			if(check(choose)) {
				if (choose < min) {
					min = choose;
					for (int i = 0; i < choose; i++) {
						ans[i] = d[i];
					}
				}
			}
			return;
		}
		for (int i = step; i < m; i++) {
			if(vis[i] == false) {
				vis[i] = true;
				d[choose] = i;
				dfs(i+1, choose+1);
				vis[i] = false;
				d[choose] = 0;
			}
		}
	}
	public static boolean check(int x) {
		for (int i = 0; i < n; i++) {
			int sum = 0;
			for (int j = 0; j < x; j++) {
				sum += flood[d[j]][i];
			}
			if (sum < need[i]) {
				return false;
			}
		}
		return true;
	}
}