LeetCode_ 3 (longest substring without repeated characters)

Title Description ：
Given a string s , Please find out that there are no duplicate characters in it Longest substrings The length of .

Example 1:
Input : s = “abcabcbb”
Output : 3
explain : Because the longest substring without repeating characters is “abc”, So its length is 3.

Example 2:
Input : s = “bbbbb”
Output : 1
explain : Because the longest substring without repeating characters is “b”, So its length is 1.

Example 3:
Input : s = “pwwkew”
Output : 3
explain : Because the longest substring without repeating characters is “wke”, So its length is 3. Please note that , you The answer must be Substring The length of ,“pwke” Is a subsequence , Not substring .

Tips ：

0 <= s.length <= 5 * 104
s By the English letters 、 Numbers 、 Symbols and spaces

class Solution {
    
    public int lengthOfLongestSubstring(String s) {
    
        int ans=0;
        if(s.equals(""))return 0;
        if(s.length()==1)return 1;
        int i=0,j=1,len=1;
        while(j<s.length()){
                            // Traverse 
            for (int k = i; k < j; k++) {
               // Traversal in the window 
                if(s.charAt(k)==s.charAt(j)){
           // Determine whether there are repeated characters in the window 
                    i=k+1;
                    len=j-i;
                    break;
                }
            }
            len++;
            if(len>ans)ans=len;
            j++;
        }
        return ans;
    }
}