Codeforces Round #306 (Div. 2) 550A - Two Substrings Solution

                               

         

Problem Link: https://codeforces.com/problemset/problem/550/A

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. ios_base::sync_with_stdio(0);
11. cin.tie(0);
12. string s;
13. cin >> s;
14. int i;
15. int l = s.size();
16. bool a = false, b = false, c = false, d = false;
17. for (int i = 0; i < l - 1; i++) {
18. if ((s[i] == 'B') && (s[i + 1] == 'A') && (s[i + 2] == 'B') &&
19. (d == false) && (c == false))
20. d = true, i += 2;
21. else if ((s[i] == 'A') && (s[i + 1] == 'B') && (s[i + 2] == 'A') &&
22. (c == false) && (d == false))
23. c = true, i += 2;
24. else if ((s[i] == 'A') && (s[i + 1] == 'B') && (a == false))
25. a = true, i++;
26. else if ((s[i] == 'B') && (s[i + 1] == 'A') && (b == false))
27. b = true, i++;
28. }
29. if ((a == true && b == true) ||
30. ((c == true || d == true) && (a == true || b == true)))
31. cout << "YES" << endl;
32. else
33. cout << "NO" << endl;
34. }

Another solutoin is given bellow :

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. ios_base::sync_with_stdio(0);
11. cin.tie(0);
12. char s[100100], *p;
13. cin >> s;
14. if ((p = strstr(s, "AB")) && strstr(p + 2, "BA"))
15. cout << "YES" << endl;
16. else if ((p = strstr(s, "BA")) && strstr(p + 2, "AB"))
17. cout << "YES" << endl;
18. else
19. cout << "NO" << endl;
20. }