[LeetCode][Python]Longest Substring Without Repeating Characters

# -*- coding: utf8 -*-
'''
__author__ = '[email protected]'
https://oj.leetcode.com/problems/longest-substring-without-repeating-characters/

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.

===Comments by Dabay===
      max_so_far                   ，         ，                。
             ，     max_so_far ，  max_so_far。
'''
class Solution:
    # @return an integer
    def lengthOfLongestSubstring(self, s):
        if len(s) <= 1:
            return len(s)
        max_so_far = 0
        longest = ""
        for char in s:
            if char in longest:
                longest = longest[(longest.index(char))+1:] + char
            else:
                longest = longest + char
                max_so_far = max(max_so_far, len(longest))
        return max_so_far


def main():
    s = Solution()
    string = "abcabcbb"
    print s.lengthOfLongestSubstring(string)


if __name__ == "__main__":
    import time
    start = time.clock()
    main()
    print "%s sec" % (time.clock() - start)