Codeforces Round 918 (Div. 4) 1915E. Romantic Glasses Solution

Problem Link :  https://codeforces.com/contest/1915/problem/E

Solution in C++:

1. /// Author : AH_Tonmoy
2. #include <bits/stdc++.h>
3. using namespace std;
4. int32_t main() {
5. ios_base::sync_with_stdio(0);
6. cin.tie(0);
7. int t;
8. cin >> t;
9. while (t--) {
10. int n ;
11. cin >> n ;
12. int a[n+2] ;
13. for(int i = 1 ; i <= n ; i++){
14. cin >> a[i] ;
15. }
16. map<long long ,long long >mp ;
17. long long sum = 0 ;
18. mp[sum] = 1 ;
19. bool ok = false ;
20. for ( int i = 1 ; i <= n ; i++ ){
21. if (i%2){
22. sum +=a[i] ;
23. }
24. else{
25. sum -=a[i] ;
26. }
27. if (mp[sum]){
28. ok = true ;
29. break ;
30. }
31. mp[sum] = 1 ;
32. }
33. if (ok) cout <<"YES\n";
34. else cout <<"NO\n";
35. }
36. return 0 ;
37. }