JAVA 数组随机取值

Question

int[] arr = {1, 2, 3, 4};
int a, b, c;
我想把 数组中 随机取3个数 赋值给abc 其中 1是必须要有的随机赋给abc,然后 2 3 4 随机再赋给其他两个变量,2 3 4 可以重复
例如:
a=1 b=2 c=2
a=2 b=3 c=1
a=3 b=1 c=3

Answer 1

import java.util.Random;
import java.util.ArrayList;

public class Main {
    public static void main(String[] args) {
        int[] arr = {1, 2, 3, 4};
        int[] result = new int[3];
        Random r = new Random();
        ArrayList<Integer> lst = new ArrayList<>();
        lst.add(0);
        lst.add(1);
        lst.add(2);

        int idx = r.nextInt(3);
        result[idx] = arr[0];
        lst.remove(Integer.valueOf(idx));

        int idx1 = r.nextInt(3) + 1;
        int idx2 = r.nextInt(3) + 1;
        result[lst.get(0)] = arr[idx1];
        result[lst.get(1)] = arr[idx2];

        int a, b, c;
        a = result[0];
        b = result[1];
        c = result[2];

        System.out.println("a = " + a + ", b = " + b + ", c = " + c);
    }
}