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  1. #include <bits/stdc++.h>
  2. using namespace std;
  3. #define int              long long int
  4. #define double           long double
  5. #define print(a)         for(auto x : a) cout << x << " "; cout << endl
  6. inline int power(int a, int b) {
  7.     int x = 1;
  8.     while (b) {
  9.         if (b & 1) x *= a;
  10.         a *= a;
  11.         b >>= 1;
  12.     }
  13.     return x;
  14. }
  15.  
  16.  
  17. const int M = 1000000007;
  18. const int N = 3e5+9;
  19. const int INF = 2e9+1;
  20. const int LINF = 2000000000000000001;
  21.  
  22. //_ ***************************** START Below *******************************
  23.  
  24. vector<pair<int,int>> a;
  25.  
  26. bool isPossible(int n, double mid){
  27.  
  28. 	double s = -1, e = -1;
  29. 	for(int i=0; i<n; i++){
  30. 		double x = a[i].first;
  31. 		double v = a[i].second;
  32.  
  33. 		double l = x-mid*v;
  34. 		double r = x+mid*v;
  35.  
  36. 		if(s==-1 && e==-1){
  37. 			s = l;
  38. 			e = r;
  39. 		}
  40. 		else if(l <= e){
  41. 			s = max(s, l);
  42. 			e = min(e, r);
  43. 		}
  44. 		else return false;
  45. 	}
  46.  
  47. 	return true;
  48. }
  49.  
  50. double consistency(int n){
  51.  
  52. 	sort(begin(a), end(a));
  53.  
  54.  
  55. 	double s = 0;
  56. 	double e = 2e9;
  57. 	double precision = 1e-7;
  58.  
  59. 	int iterations = 100;
  60. 	for(int i=1; i<=iterations; i++){
  61. 		double mid = (e+s)/2;
  62.  
  63. 		if(isPossible(n, mid)){
  64. 			e = mid;
  65. 		}
  66. 		else s = mid;
  67. 	}
  68.  
  69. 	return e;
  70.  
  71. }
  72.  
  73. void solve() {
  74.  
  75.     int n;
  76.     cin>>n;
  77.  
  78.     a.resize(n);
  79.     for(int i=0; i<n; i++){
  80.     	int x, y;
  81.     	cin>>x>>y;
  82.     	a[i] = {x,y};
  83.     }
  84.  
  85.     cout << fixed << setprecision(7) <<  consistency(n) << endl;
  86.  
  87.  
  88. }
  89.  
  90.  
  91.  
  92.  
  93.  
  94. int32_t main() {
  95.     ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
  96.  
  97.     int t = 1;
  98.     // cin >> t;
  99.     while (t--) {
  100.         solve();
  101.     }
  102.  
  103.     return 0;
  104. }
Success #stdin #stdout 0.01s 5308KB
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stdin
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5
-1 5
10 3
4 2
7 10
8 1
stdout
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1.5000000
https://ideone.com/gn50YA
language:
C++14 (gcc 8.3)
created:
9 hours ago
visibility:
public

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