func_code_string: #include <bits/stdc++.h>   using namespace std;   vector<pair<long double, int> > v;   int main() {     int n;     cin >> n;     for (int i = 1; i <= n; i++) {       long double x, y;       cin >> x >> y;       v.push_back(make_pair(atan2(y, x), i));     }     sort(v.begin(), v.end());     v.push_back(v[0]);     if (v.back().first < 0.0)       v.back().first = (2 * acos(0.0) + v.back().first + 2 * acos(0.0));     long double ans = 1e18;     int id1, id2;     for (int i = 1; i < (int)v.size(); i++) {       long double x = fabs(v[i].first - v[i - 1].first);       if (x < ans) {         ans = x;         id1 = v[i].second;         id2 = v[i - 1].second;       }     }     cout << id1 <<     << id2 << endl;     return 0;   }   