题目：

题解：

func findSubstring(s string, words []string) (ans []int) {ls, m, n := len(s), len(words), len(words[0])for i := 0; i < n && i+m*n <= ls; i++ {differ := map[string]int{}for j := 0; j < m; j++ {differ[s[i+j*n:i+(j+1)*n]]++}for _, word := range words {differ[word]--if differ[word] == 0 {delete(differ, word)}}for start := i; start < ls-m*n+1; start += n {if start != i {word := s[start+(m-1)*n : start+m*n]differ[word]++if differ[word] == 0 {delete(differ, word)}word = s[start-n : start]differ[word]--if differ[word] == 0 {delete(differ, word)}}if len(differ) == 0 {ans = append(ans, start)}}}return
}