I would be grateful, if anyone could

• point out why the below solution TLEd?

• give hints to improve the code running time?

Logic explanation in plain english:

• Create a dictionary of string, int.

• the key stores the patterns of len 19 for each number w.r.t to parity of each digit e.g ( 00000000101010111011 )

• the count of pattern is incremented, decremented accordingly.

• Ans is just a dictionary lookup for given pattern

20594344

Contest 371 DIV2 Problem C : http://codeforces.me/contest/714/problem/C