[Leetcode] Substring with Concatenation of All Words

You are given a string, S, and a list of words, L, that are all of the same length. Find all starting indices of substring(s) in S that is a concatenation of each word in L exactly once and without any intervening characters.

For example, given:
S: "barfoothefoobarman"
L: ["foo", "bar"]

You should return the indices: [0,9].
(order does not matter).

题目：给定一个字符串S，一个字符串数组L，找出S中所有这样的子串起点，该子串包含L中的所有元素。

说明：

[Leetcode] Substring with Concatenation of All Words

原文：http://www.cnblogs.com/Phoebe815/p/4003278.html