package q3

func lengthOfLongestSubstring(s string) int {
	seen := make([]bool, 256)
	maxLen := 0

	l := 0
	for r := range len(s) {
		c := s[r]
		for seen[c] {
			seen[s[l]] = false
			l++
		}
		seen[c] = true
		maxLen = max(maxLen, r-l+1)
	}
	return maxLen
}

var _ = lengthOfLongestSubstring