题解 | #全排列#

import java.util.Scanner;

/**
 * @author Zhang
 * @date 2023/2/25 20:24
 * @description
 */
public class Main {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        String sequence = scanner.nextLine();
        fullArrangement("", sequence);
    }

    static void fullArrangement(String preStr, String remainStr) {
        if (remainStr.length() == 1) {
            System.out.println(preStr + remainStr);
        } else {
            String nextPreStr = "";
            String nextRemainStr = "";
            for (int i = 0; i < remainStr.length(); i++) {
                nextPreStr = preStr + remainStr.charAt(i);

                nextRemainStr = remainStr;
                if (i == remainStr.length() - 1) {
                    nextRemainStr = nextRemainStr.substring(0, i);
                } else {
                    nextRemainStr = nextRemainStr.substring(0, i) + nextRemainStr.substring(i + 1);
                }
                fullArrangement(nextPreStr, nextRemainStr);
            }
        }
    }
}