Codeforces Global Round 4 1178B - WOW Factor Solution

  Problem Link: https://codeforces.com/contest/1178/problem/B

Solution in C++:

1. /// La ilaha illellahu muhammadur rasulullah
2. ///******Bismillahir-Rahmanir-Rahim******///
3. /// Abul Hasnat Tonmoy
4. /// Department of CSE,23rd batch
5. /// Islamic University,Bangladesh
6. ///**********ALLAH IS ALMIGHTY************///
7. #include <bits/stdc++.h>
8. using namespace std;
9. int main() {
10. string s;
11. cin >> s;
12. long long n = s.size();
13. long long a[n], b[n], x = 0, y = 0;
14. for (int i = 1; i < n; i++) {
15. if (s[i] == 'v' && s[i - 1] == 'v') {
16. x++;
17. }
18. a[i] = x;
19. }
20. for (int i = n - 2; i >= 0; i--) {
21. if (s[i] == 'v' && s[i + 1] == 'v') {
22. y++;
23. }
24. b[i] = y;
25. }
26. long long ans = 0;
27. for (int i = 1; i < n - 1; i++) {
28. if (s[i] == 'o') {
29. ans += (a[i] * b[i]);
30. }
31. }
32. cout << ans << endl;
33. }