47-java 排列组合

import java.util.HashSet;
 
public class Main1
{
	public static int ys = 0;
	public static int ys2 = 0;
	public static int N = 10;
	public static int[] a = new int[13];
	public static int[]visit = new int[13];
 
	public static void main(String[] args) { 
 
		dfs1(0);
		dfs2(0, 0);
 
		System.out.println(ys);
		System.out.println(ys2);
	}
 
	public static void dfs1(int cnt) { // 这样的是全排列: A(12,5)
		if(cnt == 5) {
			ys++;
			return ;
		}
		for(int i = 1; i <= 12; i++) {
			if(visit[i] == 0) {
				visit[i] = 1;
				a[cnt] = i;
				dfs1(cnt + 1);
				visit[i] = 0;
			}
		}
	}
	public static void dfs2(int index, int cnt) { // 这样的是不要顺序: C(12,5)
		if(cnt == 5) {
			ys2++;
			return ;
		}
		for(int i = index + 1; i <= 12; i++) {
			 a[cnt] = i;
			 dfs2(i, cnt + 1);
		}
 
	}
}