在Java中迭代地生成所有的字符串置换对

import java.util.ArrayList;
import java.util.List;

public class StringPermutations {
    public static void main(String[] args) {
        String str = "abc";
        List<String> permutations = new ArrayList<>();
        generatePermutations("", str, permutations);
        
        // 打印所有置换
        for (String permutation : permutations) {
            System.out.println(permutation);
        }
    }

    private static void generatePermutations(String prefix, String remaining, List<String> permutations) {
        int n = remaining.length();
        if (n == 0) {
            permutations.add(prefix);
        } else {
            for (int i = 0; i < n; i++) {
                generatePermutations(prefix + remaining.charAt(i), remaining.substring(0, i) + remaining.substring(i + 1, n), permutations);
            }
        }
    }
}