<p>Given a string <code>s</code>, find the length of the <strong>longest</strong> <span data-keyword="substring-nonempty"><strong>substring</strong></span> without repeating characters.</p>

<p>&nbsp;</p>
<p><strong class="example">Example 1:</strong></p>

<pre>
<strong>Input:</strong> s = &quot;abcabcbb&quot;
<strong>Output:</strong> 3
<strong>Explanation:</strong> The answer is &quot;abc&quot;, with the length of 3.
</pre>

<p><strong class="example">Example 2:</strong></p>

<pre>
<strong>Input:</strong> s = &quot;bbbbb&quot;
<strong>Output:</strong> 1
<strong>Explanation:</strong> The answer is &quot;b&quot;, with the length of 1.
</pre>

<p><strong class="example">Example 3:</strong></p>

<pre>
<strong>Input:</strong> s = &quot;pwwkew&quot;
<strong>Output:</strong> 3
<strong>Explanation:</strong> The answer is &quot;wke&quot;, with the length of 3.
Notice that the answer must be a substring, &quot;pwke&quot; is a subsequence and not a substring.
</pre>

<p>&nbsp;</p>
<p><strong>Constraints:</strong></p>

<ul>
	<li><code>0 &lt;= s.length &lt;= 5 * 10<sup>4</sup></code></li>
	<li><code>s</code> consists of English letters, digits, symbols and spaces.</li>
</ul>

class Solution {
public:
    int lengthOfLongestSubstring(string s) {
        int n = s.length();
        if(n==0 || n==1) return n;
        int maxSub = 0;
       
        for(int i=0;i<n;i++){
            string subStr = "";
            unordered_map<char,int> map;
            
            int j=i;
            for(;j<n;j++){
                subStr += s[j];
                if(map[s[j]]) break;
                else{
                    map[s[j]] = j;
                    if(j==0) map[s[j]] = n+1;
                }
            }
            if(j==n){
                if(maxSub<subStr.length()) maxSub = subStr.length();
            }else if(maxSub<(subStr.length()-1)){
                maxSub = subStr.length()-1;
            }
            if(j!=n)i = map[s[j]];
            if(j==n) i=n;
            if(map[s[j]]==n+1) i=0;
        }
        return maxSub;
    }
};
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