[LintCode] Longest Substring Without Repeating Characters-白红宇

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

Have you met this question in a real interview?

Yes

Example

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.

O(n) time

LeetCode上的原题，请参见我之前的博客。

解法一：

class Solution {public:    /**     * @param s: a string     * @return: an integer      */    int lengthOfLongestSubstring(string s) {        int res = 0, left = -1;        vector
      
        m(256, -1);        for (int i = 0; i < s.size(); ++i) {            left = max(left, m[s[i]]);            m[s[i]] = i;            res = max(res, i - left);        }        return res;    }};

解法二：

class Solution {public:    /**     * @param s: a string     * @return: an integer      */    int lengthOfLongestSubstring(string s) {        int res = 0, left = 0, right = 0;        unordered_set
      
        st;        while (right < s.size()) {            if (!st.count(s[right])) {                st.insert(s[right++]);                res = max(res, (int)st.size());            } else {                st.erase(s[left++]);            }        }        return res;    }};

本文转自博客园Grandyang的博客，原文链接：，如需转载请自行联系原博主。