Codeforces Round 923 (Div. 3) 1927 D. Find the Different Ones! Solution

 

Problem Link :  Problem Link : https://codeforces.com/contest/1927/problem/d

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 ; cin >> n ;
11. int a[n+1] ;
12. for ( int i = 1 ; i <= n ; i++){
13. cin >> a[i] ;
14. }
15. set<int>st ;
16. for( int i = 2 ; i <= n ; i++){
17. if(a[i] != a[i-1]){
18. st.insert(i) ;
19. }
20. }
21. int q ; cin >> q ;
22. while(q--){
23. int x , y ; cin >> x >> y ;
24. auto it = st.upper_bound(x) ;
25. if( it == st.end() or *it > y){
26. cout <<"-1 -1\n";
27. }
28. else{
29. int ans = *it ;
30. cout << ans - 1 <<" "<< ans <<'\n';
31. }
32. }
33. }
34. return 0 ;
35. }