Solution: String Compression

Statement

Given an array of characters, chars, compress it in place according to the following rules:

1. Start with an empty string s.

2. For each group of consecutive repeating characters in chars:

   1. If the group length is $1$, append just the character to s.

   2. Otherwise, append the character followed by the group length.

The compressed string s should not be returned separately; instead, it must be written directly into the input character array chars. Note that if a group’s length is $10$ ...