Java | Leetcode Java题解之第398题随机数索引
题目：
题解：
class Solution {
int[] nums;
Random random;
public Solution(int[] nums) {
this.nums = nums;
random = new Random();
}
public int pick(int target) {
int ans = 0;
for (int i = 0, cnt = 0; i < nums.length; ++i) {
if (nums[i] == target) {
++cnt; // 第 cnt 次遇到 target
if (random.nextInt(cnt) == 0) {
ans = i;
}
}
}
return ans;
}
}