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  1. #include<bits/stdc++.h>
  2. using namespace std;
  3.  
  4. void solve(){
  5.   int n; cin >> n;
  6.   vector<int> a(n);
  7.   for(int i = 0; i < n; i++) cin >> a[i];
  8.   for(int i = 0; i < n-1; i++){
  9.     if(abs(a[i]-a[i + 1]) <= 1){
  10.       cout << 0 << '\n';
  11.       return;
  12.     }
  13.   }
  14.   if(n == 2){
  15.     if(abs(a[0] - a[1]) <= 1) cout << 0 << '\n';
  16.     else cout << -1 << '\n';
  17.     return;
  18.   }
  19.   for(int i = 0; i < n - 1; i++){
  20.     int mn = min(a[i], a[i + 1]);
  21.     int mx = max(a[i], a[i + 1]);
  22.     for(int j = 0; j < n && j != i && j != i + 1; j++){
  23.       if(a[j] >= mn && a[j] <= mx){
  24.         cout << 1 << '\n';
  25.         return;
  26.       }
  27.       else if(abs(a[j] - mn) <= 1 || abs(a[j] - mx) <= 1){
  28.         cout << 1 << '\n';
  29.         return;
  30.       }
  31.     }
  32.   }
  33.   cout << -1 << '\n';
  34.   return;
  35. }
  36.  
  37.  
  38. int main(){
  39.     ios::sync_with_stdio(false);
  40.     cin.tie(nullptr);
  41.     int t = 1;
  42.     cin >> t;
  43.     while(t--) solve();
  44. }
Success #stdin #stdout 0.01s 5292KB
comments (?)
stdin 
1
3
2 7 5
stdout 
-1
https://ideone.com/ilZ8FR
1
language:
C++14 (clang 8.0)
created:
3 days ago
visibility:
public

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