Length of Longest Substring

lengthOfLongestSubstring.go

// solution 1

func lengthOfLongestSubstring(s string) int {

	length := len(s)

	var result []string

	// fmt.Println(s[1:4])

	for i := 0; i < length; i++ {

		for j := 0; j < length+1; j++ {

			if j < i {
				continue
			}

			if strings.Contains(s, s[i:j]) {
				if checkDuplicate(s[i:j]) {
					result = append(result, s[i:j])
				}
			}
		}

	}

	max := func(a []string) (max int) {

		if len(a) == 0 {
			return 0
		}

		max = len(a[0])
		for _, value := range a {
			if len(value) > max {
				max = len(value)
			}
		}
		return max
	}(result)

	return max
}

// solution 2

func lengthOfLongestSubstring(s string) int {

	length := len(s)

	result := map[string]int{}

	var left, right int
	var count int = 0
	for right < length {

		result[string(s[right])] += 1

		for result[string(s[right])] > 1 {
			result[string(s[left])] -= 1
			left++
		}

		if count < right-left+1 {
			count = right - left + 1
		}

		right++
	}

	return count
}