P10974.java

package BOJ;
import java.util.*;

public class P10974 {

	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		int n = sc.nextInt();
		int[] a = new int[n];
		
		for(int i=1;i<=n;i++){
			a[i-1] = i;
			System.out.print(a[i-1]+" ");
		}
		System.out.println();
		
		while(next_permutation(a)){
			for(int i=0;i<n;i++){
				System.out.print(a[i]+" ");
			}
			System.out.println();
		}

	}
	
	public static boolean next_permutation(int[] a){
		int i = a.length-1;
		while(i>0 && a[i-1]>=a[i]){
			i-=1;
		}
		
		if(i==0)
			return false;
		
		int j = a.length-1;
		while(a[i-1]>=a[j]){
			j-=1;
		}
		
		int temp = a[i-1];
		a[i-1] = a[j];
		a[j] = temp;
		
		j = a.length-1;
		while(i<j){
			temp = a[i];
			a[i] = a[j];
			a[j] = temp;
			i+=1;
			j-=1;
		}
		return true;
	}

}