Recursion-Dictionary Order(large)

#1

my code is constantly giving WA…whereas when i comment out the backtracking statment it is passed for few test cases

my code-> https://ide.codingblocks.com/s/90454
question->https://hack.codingblocks.com/contests/c/207/361

#2

use char array because when we do bactracking the index of char array is manipulated but if u r using string u have to use the erase function