Solution: Substring with Concatenation of All Words
Explore how to use the sliding window technique to solve the substring concatenation problem by dynamically managing frequency maps. Understand how to iterate with aligned windows and adjust boundaries to efficiently find all valid starting indices of concatenated word permutations in a string.
We'll cover the following...
Statement
You are given a string, s, and an array of strings, words. All strings in words are of the same length.
A concatenated string is a string that contains all the words in words exactly once, in any order, concatenated together without any intervening characters.
Formally, a concatenated string is a permutation of all words joined together. For example, if words = ["ab", "cd", "ef"], then the following are all valid concatenated strings: "abcdef", "abefcd", "cdabef", "cdefab", "efabcd", "efcdab". However, "acdbef" is not valid because it is not formed by concatenating all the words in any order.
Your task is to return all starting indices of substrings in s that are concatenated strings.
You may return the indices in any order. ...