todo

https://leetcode.com/problems/sort-colors/description/
https://leetcode.com/problems/sort-by/
https://leetcode.com/problems/sort-an-array/description/
https://leetcode.com/problems/custom-sort-string/description/
https://leetcode.com/problems/relative-sort-array/description/
https://leetcode.com/problems/sort-the-people/description/
https://leetcode.com/problems/sort-characters-by-frequency/description/
https://leetcode.com/problems/sort-array-by-increasing-frequency/description/
https://leetcode.com/problems/gcd-sort-of-an-array/description/
https://leetcode.com/problems/sort-vowels-in-a-string/description/
https://leetcode.com/problems/sort-even-and-odd-indices-independently/description/
https://leetcode.com/problems/sorting-the-sentence/description/
https://leetcode.com/problems/sorting-three-groups/description/