数组的随机洗牌

arrays random shuffle java

2022-08-31 05:22:36

我需要随机洗牌以下数组：

int[] solutionArray = {1, 2, 3, 4, 5, 6, 6, 5, 4, 3, 2, 1};

有什么功能可以做到这一点吗？

答案 1

使用集合来随机排列基元类型数组有点过分了......

它很简单，可以自己实现该函数，例如使用Fisher-Yates shuffle：

import java.util.*;
import java.util.concurrent.ThreadLocalRandom;

class Test
{
  public static void main(String args[])
  {
    int[] solutionArray = { 1, 2, 3, 4, 5, 6, 16, 15, 14, 13, 12, 11 };

    shuffleArray(solutionArray);
    for (int i = 0; i < solutionArray.length; i++)
    {
      System.out.print(solutionArray[i] + " ");
    }
    System.out.println();
  }

  // Implementing Fisher–Yates shuffle
  static void shuffleArray(int[] ar)
  {
    // If running on Java 6 or older, use `new Random()` on RHS here
    Random rnd = ThreadLocalRandom.current();
    for (int i = ar.length - 1; i > 0; i--)
    {
      int index = rnd.nextInt(i + 1);
      // Simple swap
      int a = ar[index];
      ar[index] = ar[i];
      ar[i] = a;
    }
  }
}

答案 2

这是使用：ArrayList

List<Integer> solution = new ArrayList<>();
for (int i = 1; i <= 6; i++) {
    solution.add(i);
}
Collections.shuffle(solution);