func_code_string: #include <bits/stdc++.h>   using namespace std;   const int MAX = 400;   struct hh {     double x, y;   } a[MAX];   double jisuan(hh a, hh b, hh c) {     double x1, y1, x2, y2;     x1 = b.x - a.x;     y1 = b.y - a.y;     x2 = c.x - a.x;     y2 = c.y - a.y;     return (x1 * y2 - x2 * y1) / 2;   }   int main() {     int n;     cin >> n;     for (int i = 0; i < n; i++) {       cin >> a[i].x >> a[i].y;     }     double area, l, r;     area = 0;     for (int i = 0; i < n; i++) {       for (int j = i + 1; j < n; j++) {         l = r = 0;         for (int k = 0; k < n; k++) {           double w = jisuan(a[i], a[j], a[k]);           if (w > 0 && w > l)             l = w;           else if (w < 0 && -w > r)             r = -w;         }         if (l + r > area && l > 0 && r > 0) area = l + r;       }     }     printf( %.6f n , area);     return 0;   }   