https://leetcode.com/problems/decode-string
- create a stack that will hold the history of chars
- insert until you get to a closer bracket
] - when you get to a closer bracket, you need to find:
- the string between the brackets
- the multiplier before the opening bracket
[
- the string is easy, just connect chars until
[ - the multiplier is from
[until end of stack or char is not a digit - as we get both values, we decode the string and push it to the stack
- we push back to the stack in case this is a string inside a string