@author problem is awesome but please add some extra test cases. Test cases are so weak that completely wrong solutions got accepted for 80 points! I myself wasted 2-3 hours thinking that there is some edge cases that i’m missing but afterwards i found that my approach was completely wrong. So, please add some strong cases as it will help others who solve this nice problem later 
Can anyone explain the solution of this problem using suffix arrays?
The testers solution uses suffix arrays but i am unable to understand it.
can someone please explain tester’s solution?