C ++中的随机选择索引
范例（C++）
让我们看下面的实现以更好地理解-
#include <bits/stdc++.h>
using namespace std;
class Solution {
public:
vector <int> v;
Solution(vector<int>& nums) {
srand(time(NULL));
v = nums;
}
int pick(int target) {
int ret = -1;
int cnt = 1;
for(int i = 0; i < v.size(); i++){
if(v[i] == target){
if(rand() % cnt++ == 0) ret = i;
}
}
return ret;
}
};
main(){
vector<int> v = {1,2,3,3,3};
Solution ob(v);
cout << (ob.pick(3));
}输入值
Initialize with [1,2,3,3,3] Call pick(3) to get random index positions
输出结果
4 3 4 2