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  1. #include <bits/stdc++.h>
  2. using namespace std;
  3.  
  4. int main() {
  5.     int n, x;
  6.     cin >> n;
  7.  
  8.     vector<int> a(n);
  9.     for(int i = 0; i < n; i++) {
  10.         cin >> a[i];
  11.     }
  12.      cin >> x;
  13.     int l = 0, r = n - 1;
  14.      while(l <= r) {
  15.         int m = (l + r) / 2;
  16.  
  17.         if(a[m] == x) {
  18.             cout << m << endl;
  19.             return 0;
  20.         }
  21.         if(a[l] <= a[m]) {
  22.             if(x >= a[l] && x < a[m])
  23.                 r = m - 1;
  24.             else
  25.                 l = m + 1;
  26.         }
  27.         else {
  28.             if(x > a[m] && x <= a[r])
  29.                 l = m + 1;
  30.             else
  31.                 r = m - 1;
  32.         }
  33.     }
  34.  
  35.     cout << -1 << endl;
  36.     return 0;
  37. }
  38.  
Success #stdin #stdout 0s 5316KB
comments (?)
stdin
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7
4 5 6 7 0 1 2
3
stdout
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-1
https://ideone.com/eRbqLJ
language:
C++ (gcc 8.3)
created:
4 hours ago
visibility:
public

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