LeetCode第三题（Longest Substring Without Repeating Characters）

Longest Substring Without Repeating Characters

Given a string, find the length of the longest substring without repeating characters.

Examples:

Given "abcabcbb", the answer is "abc", which the length is 3.
Given "bbbbb", the answer is "b", with the length of 1.
Given "pwwkew", the answer is "wke", with the length of 3. 
Note that the answer must be a substring, "pwke" is a subsequence and not a substring.

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python代码

class Solution:
    def lengthOfLongestSubstring(self, s):
        """
        :type s: str
        :rtype: int
        """
        lls = 1
        if len(s) == 0:
            return 0
        if len(s) == 1:
            return 1
        i = 0
        j = 1
        while j < len(s):
            pos = s.find(s[j], i, j)
            if pos != -1:
                lls = max(lls, j-i)
                i = pos + 1
            j += 1
        if s.find(s[len(s)-1], i, len(s)-1) == -1:
            lls = max(lls, len(s)-i)
        return lls

PS:这题有多种解法，博主这种虽然巧妙用了find()函数，但已经相当于直接暴力解了，据说用dict也可以解，而且效率更高，先留着以后有空来试一下