Problems to resolve or solve
very complex solutions need to simplify https://leetcode.com/problems/replace-all-s-to-avoid-consecutive-repeating-characters/
simplify https://leetcode.com/problems/largest-substring-between-two-equal-characters/
simplify https://leetcode.com/problems/longest-common-prefix/
simplify https://leetcode.com/problems/greatest-common-divisor-of-strings/submissions/