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  1. #include <bits/stdc++.h>
  2. using namespace std;
  3. using ll = long long;
  4. #define sz(st) int(st.size())
  5. #define all(st) st.begin(), st.end()
  6.  
  7. void Solve() {
  8.     int n;
  9.     cin >> n;
  10.     vector<int> x(n), v(n);
  11.     for (int i = 0; i < n; i++)
  12.         cin >> x[i] >> v[i];
  13.  
  14.     auto is_good = [&](double time) {
  15.        double left = -1e9, right = 1e9;
  16.         for (int i = 0;i<n;i++) {
  17.             left = max(left, x[i] - v[i] * time);
  18.             right = min(right, x[i] + v[i] * time);
  19.         }
  20.         return left <= right;
  21.     };
  22.  
  23.     double l = 0, r = 1e9, ans = 0;
  24.     for (int i = 0; i < 100; i++) {
  25.         double m = (l + r) / 2;
  26.         if (is_good(m))
  27.             r = m - 1, ans = m;
  28.         else
  29.             l = m + 1;
  30.     }
  31.     cout << fixed << setprecision(10) << ans;
  32. }
  33.  
  34. signed main() {
  35.     ios_base::sync_with_stdio(false);
  36.     cin.tie(nullptr);
  37.     int t = 1;
  38.     //cin >> t;
  39.     for (int tc = 1; tc <= t; tc++) {
  40.         Solve();
  41.         cout << "\n";
  42.     }
  43.     return 0;
  44. }
  45.  
Success #stdin #stdout 0.01s 5284KB
comments (?)
stdin
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5
-1 5
10 3
4 2
7 10
8 1
stdout
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1.5000000000
https://ideone.com/gP61X7
language:
C++ (gcc 8.3)
created:
2 days ago
visibility:
public

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