30. 串联所有单词的子串 Golang实现

func findSubstring(s string, words []string) []int {
    if len(words) == 0 || len(s) < len(words)*len(words[0]) {
        return []int{}
    }

    wordsCount := make(map[string]int)
    for _, word := range words {
        wordsCount[word]++
    }
    wordLen := len(words[0])
    totalWords := len(words)
    res := []int{}

    for i := 0; i < wordLen; i++ {
        left := i
        count := 0
        windowCount := make(map[string]int)

        for right := i; right <= len(s)-wordLen; right += wordLen {
            word := s[right : right+wordLen]
            if _, exists := wordsCount[word]; exists {
                windowCount[word]++
                count++

                for windowCount[word] > wordsCount[word] {
                    leftWord := s[left : left+wordLen]
                    windowCount[leftWord]--
                    count--
                    left += wordLen
                }

                if count == totalWords {
                    res = append(res, left)
                }
            } else {
                windowCount = make(map[string]int)
                count = 0
                left = right + wordLen
            }
        }
    }
    return res
}