I was trying to solve problem from SRM 698. I can't think of any approach for this problem. Firstly I thought, lets iterate through 0 to n .. and see if I delete i character from string will I get S = T + T ..but after some time I realised it's difficult to keep track which characters to be deleted and so on.. Recently in Educational Round at Codeforces I got another problem.. I keep getting these types of problems all the time but never solved them . Can you please help me developing an approach for all these types of problems where they delete, insert and do all kind of operations like this problem.. Also could not find editorials for that match.. if you find please share the link ..