func_code_string: #include <bits/stdc++.h>   using namespace std;   double EPS = 1e-11;   double a[4];   double p[4][2] = {{-1, -1}, {1, -1}, {-1, 1}, {1, 1}};   bool poss(double thr) {     double min03 = numeric_limits<double>::infinity();     double max03 = -numeric_limits<double>::infinity();     double min12 = numeric_limits<double>::infinity();     double max12 = -numeric_limits<double>::infinity();     for (int i = 0; i < 4; i++) {       min03 = min(min03, (a[0] + thr * p[i][0]) * (a[3] + thr * p[i][1]));       min12 = min(min12, (a[1] + thr * p[i][0]) * (a[2] + thr * p[i][1]));       max03 = max(max03, (a[0] + thr * p[i][0]) * (a[3] + thr * p[i][1]));       max12 = max(max12, (a[1] + thr * p[i][0]) * (a[2] + thr * p[i][1]));     }     return !(max03 < min12 || max12 < min03);   }   int main() {     ios_base::sync_with_stdio(false);     cin.tie(NULL);     cout.tie(NULL);     for (int i = 0; i < 4; i++) cin >> a[i];     double lo = 0, hi = 1e9;     for (int i = 0; i < 10000; i++) {       const double mid = (lo + hi) / 2;       if (poss(mid))         hi = mid;       else         lo = mid;     }     cout << setprecision(20) << lo << endl;     return 0;   }   