Given a list of words, L, that are all the same length, and a string, S, find the starting position of the substring of S that is a concatenation of each word in L exactly once and without any intervening characters. This substring will occur exactly once in S. Example: L: "fooo", "barr", "wing", "ding", "wing" S: "lingmindraboofooowingdingbarrwingmonkeypoundcake" Word found in joining L and also found in S: "fooowingdingbarrwing" Answer: 13 L: "mon", "key" S: "monkey Word found in joining L and also found in S: "monkey Answer: 0 L: "a", "b", "c", "d", "e" S: "abcdfecdba" Word found in joining L and also found in S: "ecdba Answer: 5