func_code_string: #include <bits/stdc++.h>   using namespace std;   const int N = 5e5 + 9;   struct Node {     double st, ed, dir;   } p[N];   struct flag {     double num, id;   } q[N];   bool cmp(flag a, flag b) { return a.num < b.num; }   int main() {     int n, m, i, j, k;     while (~scanf( %d , &n)) {       for (i = 0; i < n; ++i) {         scanf( %lf%lf , &p[i].st, &p[i].dir);       }       double L = 0, R = 1e9 + 10, mid, ans = -1;       for (j = 0; j < 100; ++j) {         mid = (L + R) / 2;         bool ok = false;         double Max = -1e50;         for (i = 0; i < n; ++i) {           p[i].ed = p[i].st + p[i].dir * mid;           if (p[i].dir >= 0) {             Max = max(Max, p[i].ed);           } else {             if (p[i].ed <= Max) {               ok = true;               break;             }           }         }         if (ok) {           ans = mid;           R = mid;         } else {           L = mid;         }       }       printf( %.20f n , ans);     }     return 0;   }   