fork download
copy 
  1. #include <bits/stdc++.h>
  2. using namespace std;
  3.  
  4. int main() {
  5.     ios::sync_with_stdio(false);
  6.     cin.tie(nullptr);
  7.  
  8.     int t;
  9.     cin >> t;
  10.  
  11.     while (t--) {
  12.         int n;
  13.         cin >> n;
  14.  
  15.         vector<int> a(n);
  16.         for (int i = 0; i < n; i++) cin >> a[i];
  17.  
  18.         auto check = [&](int i, int v) {
  19.             if (i >= 0) return v == a[i] + a[i + 2] - a[i + 4];
  20.             return false;
  21.         };
  22.  
  23.         unordered_map<int, int> cnt;
  24.         long long ans = 0;
  25.  
  26.         for (int i = 0; i < n - 4; i++) {
  27.             int v = a[i] + a[i + 2] - a[i + 4];
  28.             int c = cnt[v];
  29.             int oc = check(i - 2, v) + check(i - 4, v);
  30.             ans += c - oc;
  31.             cnt[v] = c + 1;
  32.         }
  33.  
  34.         cout << ans << '\n';
  35.     }
  36. }
  37.  
Success #stdin #stdout 0s 5320KB
comments (?)
stdin
copy 
Standard input is empty
stdout
copy 
Standard output is empty
https://ideone.com/2CMgE1
language:
C++ (gcc 8.3)
created:
10 hours ago
visibility:
public

Share or Embed source code

Discover > Sphere Engine API

The brand new service which powers Ideone!

Discover > IDE Widget

Widget for compiling and running the source code in a web browser!