func_code_string: #include <bits/stdc++.h>   using namespace std;   int n;   struct particle {     int x, v;   } particles[500002];   bool possible(long double time) {     long double maxRightyX = -1e19;     for (int i = 1; i <= n; i++) {       if (particles[i].v > 0) {         maxRightyX = max(particles[i].x + particles[i].v * time, maxRightyX);       } else if (maxRightyX >= particles[i].x + particles[i].v * time) {         return true;       }     }     return false;   }   void bin() {     long double l = 0, r = 1000000000;     while (l + 0.0000000001 < r) {       long double mid = (l + r) / 2;       if (possible(mid))         r = mid;       else         l = mid + 0.0000000001;     }     cout << fixed << setprecision(10);     if (possible(l)) {       cout << l;     } else if (possible(r)) {       cout << r;     } else {       cout <<  -1 ;     }     cout <<   n ;   }   int main() {     ios_base::sync_with_stdio(0);     cin.tie(0);     cin >> n;     for (int i = 1; i <= n; i++) cin >> particles[i].x >> particles[i].v;     bin();     return 0;   }   