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  1. #include<bits/stdc++.h>
  2. using namespace std;
  3. #define endl '\n'
  4. #define int long long
  5. const int MOD = pow(10,9)+7;
  6. const int MOD2 = 998244353;
  7. const int INF = LLONG_MAX/2;
  8.  
  9. int primes[1000000];
  10.  
  11. void seive(){
  12.     fill(primes, primes + 1000000, 1);
  13.     primes[0] = primes[1] = 0;
  14.     for(int i = 2 ; i*i < 1000000 ; i++){
  15.         if(primes[i]){
  16.             for(int j = i*i ; j < 1000000 ; j += i){
  17.                 primes[j] = 0;
  18.             }
  19.         }
  20.     }
  21.     for(int i = 1 ; i < 1000000 ; i++){
  22.         primes[i] += primes[i-1];
  23.     }
  24. }
  25. int factorial(int n){
  26.     if(n==0){
  27.         return 1;
  28.     }
  29.     return (n*(factorial(n-1)))%MOD;
  30. }
  31. bool isPrime(int n){
  32.     if(n <= 1) return false;
  33.     for(int i = 2 ; i*i <= n ; i++){
  34.         if(n % i == 0) return false;
  35.     }
  36.     return true;
  37. }
  38.  
  39. int power(int a, int b){
  40.     if(b == 0) return 1;
  41.     a %= MOD;
  42.     int value = power(a, b / 2);
  43.     if(b % 2 == 0){
  44.         return (value * value) % MOD;
  45.     } else {
  46.         return ((value * value) % MOD * (a % MOD)) % MOD;
  47.     }
  48. }
  49.  
  50. int gcd(int a, int b){
  51.     if(a == 0) return b;
  52.     return gcd(b % a, a);
  53. }
  54. void solve() {
  55.     int n,target;
  56.     cin>>n>>target;
  57.     int nums[n];
  58.     for(int i = 0 ; i<n ; i++){
  59.         cin>>nums[i];
  60.     }
  61.     int l = 0,r=n-1;
  62.     int ans = -1;
  63.     while(l<=r){
  64.         int mid = l+((r-l)/2);
  65.         if(nums[mid]==target){
  66.             ans = mid;
  67.             break;
  68.         }
  69.         if(nums[mid]>=nums[0]){
  70.             if(nums[mid]<target || nums[0]>target) l = mid+1;
  71.             else r = mid-1;
  72.         }
  73.         else{
  74.             if(nums[mid]>target || target>nums[n-1]) r = mid-1;
  75.             else l = mid+1;
  76.         }
  77.     }
  78.     cout<<ans<<endl;
  79. }
  80.  
  81. signed main(){
  82.     ios::sync_with_stdio(false); cin.tie(NULL);
  83.     int t;
  84.     cin >> t;
  85.     while(t--){
  86.         solve();
  87.     }
  88.     return 0;
  89. }
  90.  
  91.  
Success #stdin #stdout 0.01s 5308KB
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stdin
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4 5 6 7 0 1 2
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stdout
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4
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https://ideone.com/Lu6w5Z
language:
C++14 (gcc 8.3)
created:
1 day ago
visibility:
public

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