[C ++ 14]我正在使用配对，但没有输出

Question

I was writing a code to sort and output the number by using "pair". I tried some cases bat there was no output. How should I rewrite the code?

#include <iostream>
#include <algorithm>
#include <map>
using namespace std;

int main()
{
    int k, i, n;
    cin >> n;
    pair<int, int> a[n];
    for (i = 0; i < n; i++) {
        cin >> k;
        a[i].first = -k;
        a[i].second = i + 1;
    }
    sort(a, a + n);
    for (i = 0; i++; i < n) {
        cout << a[i].second;
    }
}

Answer 1

for(i=0;i++;i<n){

您打算将其编写为：

for(i=0;i<n;i++){