func_code_string: #include <bits/stdc++.h>   using namespace std;   template <class T>   T abs(T x) {     if (x < 0)       return -x;     else       return x;   }   int main() {     double A, B, C, D;     scanf( %lf%lf , &A, &B);     scanf( %lf%lf , &C, &D);     if (A * D > B * C) {       swap(A, B);       swap(D, C);     }     double l = 0, r = 1e9;     for (int T = 0; T < 200; ++T) {       double mid = (l + r) / 2.0;       bool flag = false;       double a = A - mid;       for (int i = 0; i < 2; ++i) {         double b = B - mid;         for (int j = 0; j < 2; ++j) {           double c = C - mid;           for (int u = 0; u < 2; ++u) {             double d = D - mid;             for (int v = 0; v < 2; ++v) {               if (a * d > b * c) {                 flag = true;               }               d += mid;               d += mid;             }             c += mid;             c += mid;           }           b += mid;           b += mid;         }         a += mid;         a += mid;       }       if (flag)         r = mid;       else         l = mid;     }     printf( %.12f n , l);     return 0;   }   