java - 打乱字符串时防止重复字母？

Question

我正在创建一个程序，它将输出字符串中的字母，但是是乱序的。它有效，但没有办法阻止一封信多次出现。我该怎么办？

我的代码:

import java.util.Random;


public class Final {

    public static void main(String[] args) {
        Random rand = new Random();
        String str = "pumpkinpie";

        String[] split = str.split("");
        for(int i = 0; i < split.length; i++){
            int randomLet = rand.nextInt(split.length);
            System.out.print(split[randomLet]);
        }

    }

}

Answer 1

您可以将 String 中的每个字符添加到 ArrayList 中，并使用 Collections.shuffle() 方法对其进行打乱，该方法也接受 Random 实例:

    //1. initiate the string you want to shuffle
    String originalString = "pumkinpie";
    //2. initiate a List into which the characters will be added
    List<Character> characterList= new ArrayList<Character>();
    //3. add each character from the String to the List
    for (char character : originalString.toCharArray()) {
        characterList.add(character);
    };
    //4. shuffle using Collections.shuffle
    Collections.shuffle(characterList, new Random());
    //5. print each character
    for (Character character : characterList) {
        System.out.println(character);
    }