Problem source: click

The problem states that you'll be given some queries of 2 types. You will either be asked to add a binary digit at the end of the existing string or you'll be asked to delete the last digit. After each operation, you're required to print the longest palindromic substring of that string.

I am aware of a solution involving hashing (Editorial). But I'm wondering how the regular palindromic tree can be modified to handle this.