https://leetcode.com/problems/longest-substring-without-repeating-characters/description/
Given a string, find the length of the longest substring without repeating characters.
Example 1:
Input: "abcabcbb"
Output: 3
Explanation: The answer is "abc", with the length of 3.
Example 2:
Input: "bbbbb"
Output: 1
Explanation: The answer is "b", with the length of 1.
Example 3:
Input: "pwwkew"
Output: 3
Explanation: 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.
代码：
class Solution {
public:
int lengthOfLongestSubstring(string s) {
map<char, int> mp;
mp.clear();
int ans = 0, l = 0;
for(int i = 0; i < s.length(); i ++) {
if(mp[s[i]] == 0 || mp[s[i]] < l)
ans = max(ans, i - l + 1);
else l = mp[s[i]];
mp[s[i]] = i + 1;
}
return ans;
}
};