题目描述
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.
题目思路
- 思路一、参考
class Solution {
public:
int lengthOfLongestSubstring(string s) {
vector<int> dict(256, -1);
int len = s.size();
int start = -1, maxstr = 0;
for(int i=0; i < len; i++){
if(dict[s[i]] > start){
start = dict[s[i]];
}
dict[s[i]] = i;
maxstr = max(maxstr, i-start);
}
return maxstr;
}
};
