Frequency Count

Find the smallest substring of s that contains all characters of t, including duplicates.

Find all starting indices where a concatenation of all given words (each of equal length) forms a substring.

Find all start indices where an anagram of pattern p occurs in string s.

Given two strings, determine if one string's permutation is a substring of the other.

Determine the minimum number of intervals needed to execute all tasks given a cooldown period between identical tasks.