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.
Example 4:
Input: s = "" Output: 0
Constraints:
0 <= s.length <= 5 * 104
s consists of English letters, digits, symbols and spaces.
Solution:
class Solution {
public int lengthOfLongestSubstring(String s) {
Set<Character> set = new HashSet<Character>();
int i=0, j=0, ans=0;
while(j<s.length())
{
if(!set.contains(s.charAt(j)))
{
set.add(s.charAt(j));
j++;
ans=Math.max(ans,j-i);
}
else
{
set.remove(s.charAt(i));
i++;
}
}
return ans;
}
}