3-2-5.java

import java.util.Arrays;
import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        String A = scanner.next();
        char[] arr = A.toCharArray();
        Arrays.sort(arr);
        do {
            System.out.println(new String(arr));
        } while (nextPermutation(arr));
    }

    public static boolean nextPermutation(char[] arr) {
        int i = arr.length - 2;
        while (i >= 0 && arr[i] >= arr[i + 1]) {
            i--;
        }
        if (i < 0) {
            return false;
        }
        int j = arr.length - 1;
        while (arr[j] <= arr[i]) {
            j--;
        }
        swap(arr, i, j);
        reverse(arr, i + 1, arr.length - 1);
        return true;
    }

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

    public static void reverse(char[] arr, int i, int j) {
        while (i < j) {
            swap(arr, i, j);
            i++;
            j--;
        }
    }
}