func_code_string: #include <bits/stdc++.h>   using namespace std;   const int N = 200000;   long long x[N], y[N];   vector<int> ids[N];   int order[N];   long long cross(int a, int b, int c) {     return x[c] * y[c] * (x[b] * y[a] - x[a] * y[b]);   }   int main() {     ios_base::sync_with_stdio(false);     cin.tie(nullptr);     int n;     cin >> n;     for (int i = 0; i < n; ++i) {       cin >> x[i] >> y[i];     }     iota(order, order + n, 0);     sort(order, order + n,          [&](int a, int b) { return x[a] == x[b] ? y[a] > y[b] : x[a] > x[b]; });     vector<int> hull;     for (int i = 0, j = 0; i < n; i = j) {       int a = order[i];       while (hull.size() >= 2) {         int b = hull[hull.size() - 1], c = hull[hull.size() - 2];         if (cross(a, c, b) + cross(b, a, c) + cross(c, b, a) >= 0) {           break;         }         hull.pop_back();       }       hull.push_back(a);       while (j < n && x[order[j]] == x[a] && y[order[j]] == y[a]) {         ids[a].push_back(order[j++]);       }     }     while (hull.size() >= 2) {       int a = hull[hull.size() - 1], b = hull[hull.size() - 2];       if (y[b] < y[a]) {         break;       }       hull.pop_back();     }     vector<int> ans;     for (auto i : hull) {       ans.insert(ans.begin(), ids[i].begin(), ids[i].end());     }     sort(ans.begin(), ans.end());     for (auto i : ans) {       cout << i + 1 <<    ;     }     cout <<   n ;   }   