Get Equal Substrings Within Budget - Leetcode 1208 - Java

Problem Description
Program to longest substring of s that can be changed to be same as the corresponding substring of t with the cost less than equal to maxCost.

[abhaysagarkargeti]

this was asked in my interview OA, i calculated the cost before hand by storing the cost of operation for each index into an array and then just used it while checking for the answer