Given a string s, find the length of the longest substring without repeating characters.
Example 1:
Input: s = “abcabcbb”
Output: 3
Explanation: The answer is “abc”, with the length of 3.
Example 2:
Input: s = “bbbbb”
Output: 1
Explanation: The answer is “b”, with the length of 1.
Example 3:
Input: s = “pwwkew”
Output: 3
Explanation: The answer is “wke”, with the length of 3.
Notice that the answer must be a substring, “pwke” is a subsequence and not a substring.
class Solution {
public:
int lengthOfLongestSubstring(string str) {
int n = str.size();
int res = 0;
for (int i = 0; i < n; i++) {
vector<bool> visited(256);
for (int j = i; j < n; j++) {
if (visited[str[j]] == true)
break;
else {
res = max(res, j - i + 1);
visited[str[j]] = true;
}
}
visited[str[i]] = false;
}
return res;
}
};