全排列 full permutation

import java.util.Scanner;
public class Main {

	private static int count;
	public static void main(String[] args) {
		
		Scanner in = new Scanner(System.in);
		
		int set = in.nextInt();
		int num[] = new int[set];
		
		for(int i=0;i<set;i++) {
			
			num[i] = in.nextInt();
		}
		int len = num.length;
		permutation(num,0,len);
	//System.out.println(count);
	}
	
	
	public static void permutation(int num[],int start,int len) {
		
		if(start==len-1) {//找到一种排列情况
			//count++;
			for(int k=0;k<len;k++) {
				System.out.print(num[k]+" ");
			}
			System.out.println();
		}
		for(int i=start;i<len;i++) {
			
			if(i==start||num[i]!=num[start]) {//两个数一样的前提下就不发生交换
				swap(num,i,start);
				permutation(num,start+1,len);//递归
				swap(num,i,start);//换回来
			}
			
		}
	}
	
	
	public static void swap(int num[],int i,int j) {
		
		int tempt = num[i];
		num[i] = num[j];
		num[j] = tempt;
	}
}