func_code_string: #include <bits/stdc++.h>   using namespace std;   int n, m;   struct pos {     long long x, y;     bool operator<(const pos &p) const {       if (x != p.x) return x < p.x;       return y < p.y;     }   } A[200005], stk[200005];   bool check(pos a, pos b, pos c) {     return (c.y - a.y) * (b.x - c.x) <= (b.y - c.y) * (c.x - a.x);   }   int main() {     scanf( %d , &n);     for (int i = 1; i <= n; i++) {       long long x, y;       scanf( %lld%lld , &x, &y);       y -= x * x, A[i] = (pos){x, y};     }     sort(A + 1, A + n + 1);     int cnt = 0;     for (int i = 1; i <= n; i++) {       if (i != n && A[i].x == A[i + 1].x) continue;       while (cnt > 1 && check(stk[cnt - 1], A[i], stk[cnt])) cnt--;       stk[++cnt] = A[i];     }     printf( %d n , cnt - 1);     return 0;   }   