
You are given two strings s and sub . You are also given a 2D character array mappings where mappings[i] = [old _i , new _i ] indicates that you may perform the following operation any number of times:
Replace a character old _i of sub with new _i .
Each character in sub cannot be replaced more than once.
Return true if it is possible to make sub a substring of s by replacing zero or more characters according to mappings . Otherwise, return false .
A substring is a contiguous non-empty sequence of characters within a string.
1 <= sub.length <= s.length <= 50000 <= mappings.length <= 1000mappings[i].length == 2old _i != new _is and sub consist of uppercase and lowercase English letters and digits.old _i and new _i are either uppercase or lowercase English letters or digits.