SDUT-1163 C语言实验——排列(JAVA*)

C语言实验——排列

Time Limit: 1000 ms  Memory Limit: 65536 KiB

Submit  Statistic

Problem Description

有4个互不相同的数字，请按序输出由其中三个不重复数字组成的排列。

Input

4个整数。

Output

所有排列，输出顺序见样例。

Sample Input

1 2 3 4

Sample Output

1 2 3
1 3 2
2 1 3
2 3 1
3 1 2
3 2 1
1 2 4
1 4 2
2 1 4
2 4 1
4 1 2
4 2 1
1 3 4
1 4 3
3 1 4
3 4 1
4 1 3
4 3 1
2 3 4
2 4 3
3 2 4
3 4 2
4 2 3
4 3 2

Hint

 

Source

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//package leslie1;

//import java.io.*;
//import java.math.*;
//import java.text.*;
//import java.math.BigInteger;
import java.util.*;

public class Main {
	static int a[] = new int[4];
	static int b[] = new int[4];
	static int c[] = new int[4];
	static int v[] = new int[10086];

	public static void DFS(int x) {
		for (int i = 0; i < 3; i++) {
			if (v[b[i]] == 0) {
				v[b[i]] = 1;
				c[x] = b[i];
				if (x == 3)
					for (int j = 1; j <= 3; j++)
						System.out.printf("%d%c", c[j], j == 3 ? '\n' : ' ');
				else
					DFS(x + 1);
				v[b[i]] = 0;
			}
		}
	}

	public static void main(String[] args) {
		Scanner cin = new Scanner(System.in);
		for (int i = 0; i < 4; i++)
			a[i] = cin.nextInt();
		Arrays.sort(a);
		b[0] = a[0];
		b[1] = a[1];
		b[2] = a[2];
		DFS(1);
		Arrays.fill(v, 0);
		b[0] = a[0];
		b[1] = a[1];
		b[2] = a[3];
		DFS(1);
		Arrays.fill(v, 0);
		b[0] = a[0];
		b[1] = a[2];
		b[2] = a[3];
		DFS(1);
		Arrays.fill(v, 0);
		b[0] = a[1];
		b[1] = a[2];
		b[2] = a[3];
		DFS(1);
		cin.close();
	}
}