모든 순열

import java.util.Scanner;
import java.util.Stack;

public class BOJ_10974 {

    static int[] arr;

    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        arr = new int[n];
        for (int i = 0; i < n; i++) {
            arr[i] = i + 1;
        }

        print();
        while (true) {
            if (nextPermutation())
                continue;
            else break;
        }
    }

    private static boolean nextPermutation() {

        int idx = arr.length - 1;

        while (true) {

            if (idx == 0) {
                return false;
            }

            if (arr[idx - 1] > arr[idx]) {
                idx -= 1;
                continue;
            }

            int i = idx;
            int j = -1;
            for (int k = idx - 1; k < arr.length; k++) {
                if (arr[idx - 1] < arr[k])
                    j = k;
            }

            if (j != -1) {
                swap(i - 1, j);
                reverse(i);
                print();
                break;
            }
        }

        return true;
    }

    private static void print() {
        StringBuilder sb = new StringBuilder();
        for (int i = 0; i < arr.length; i++) {
            sb.append(arr[i]);
            if (i != arr.length - 1)
                sb.append(" ");
        }
        System.out.println(sb.toString());
    }

    private static void reverse(int idx) {
        Stack<Integer> stack = new Stack<>();
        for (int i = idx; i < arr.length; i++) {
            stack.add(arr[i]);
        }
        for (int i = idx; i < arr.length; i++) {
            arr[i] = stack.pop();
        }
    }

    private static void swap(int i, int j) {
        int temp = arr[i];
        arr[i] = arr[j];
        arr[j] = temp;
    }
}