Go语言无重复字符的最长子串

func lengthOfLongestSubstring(s string)int{ 
	var length = 0 
	var max = 0 
	var start = 0//慢指针 
	var end = 0//快指针 
	for end<len(s){ 
		tmpChar:=s[end] 
		for i:=start;i<end;i++{ 
			if tmpChar==s[i]{ 
				start = i+1 
				length = end-start 
				break 
			} 
		} 
		length++ 
                end++ 
		max = int(math.Max(float64(length), float64(max))) 
	} 
 
	return max 
}