package longestsubstringwithoutrepeatingcharacters

// 3. 无重复字符的最长子串
// https://leetcode.cn/problems/longest-substring-without-repeating-characters/

func lengthOfLongestSubstring(s string) int {
	if s == "" {
		return 0
	}
	mp := make(map[byte]int, 0)
	ml := 1
	start := 0
	bs := []byte(s)
	for i, v := range bs {
		if _, ok := mp[v]; ok {
			nStart := mp[v] + 1
			// 删除之前的所有内容
			for j := start; j < nStart; j++ {
				delete(mp, bs[j])
			}
			start = nStart
			mp[v] = i
		} else {
			mp[v] = i
			if ml < len(mp) {
				ml = len(mp)
			}
		}
	}
	return ml
}