kazi1@的部落格

Given a string, find the length of the longest substring without repeating characters. For example, the longest substring without repeating letters for "abcabcbb" is "abc", which the length is 3. For "bbbbb" the longest substring is "b", with the length of 1.

class Solution(object):
    def lengthOfLongestSubstring(self, s):
        """
        :type s: str
        :rtype: int
        """
        if len(s) < 1:
            return 0
        hmap = {}
        longest = 0
        left = -1
        right = 0
        while right < len(s):
            if s[right] in hmap:
                d = right - left - 1
                if longest < d:
                    longest = d
                if hmap[s[right]] > left:
                    left = hmap[s[right]]
            hmap[s[right]] = right
            right += 1
        # end of string
        d = right - left - 1
        if longest < d:
            longest = d
        return longest
 

v2, nice and clean

class Solution(object):
    def lengthOfLongestSubstring(self, s):
        """
        :type s: str
        :rtype: int
        """
        hmap = {}
        left = 0
        longest = 0
        for right in xrange(len(s)):
            if s[right] in hmap:
                left = max(left, hmap[s[right]]+1)
            hmap[s[right]] = right
            longest = max(longest, right - left + 1)
        return longest