<p>You are given a string <code>s</code>. An <strong>awesome</strong> substring is a non-empty substring of <code>s</code> such that we can make any number of swaps in order to make it a palindrome.</p>

<p>Return <em>the length of the maximum length <strong>awesome substring</strong> of</em> <code>s</code>.</p>

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

<pre>
<strong>Input:</strong> s = &quot;3242415&quot;
<strong>Output:</strong> 5
<strong>Explanation:</strong> &quot;24241&quot; is the longest awesome substring, we can form the palindrome &quot;24142&quot; with some swaps.
</pre>

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

<pre>
<strong>Input:</strong> s = &quot;12345678&quot;
<strong>Output:</strong> 1
</pre>

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

<pre>
<strong>Input:</strong> s = &quot;213123&quot;
<strong>Output:</strong> 6
<strong>Explanation:</strong> &quot;213123&quot; is the longest awesome substring, we can form the palindrome &quot;231132&quot; with some swaps.
</pre>

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

<ul>
	<li><code>1 &lt;= s.length &lt;= 10<sup>5</sup></code></li>
	<li><code>s</code> consists only of digits.</li>
</ul>

class Solution {
public:
    int longestAwesome(string s) {
        int n=s.size();
        unordered_map<int,int>v;
        int x=0;int ans=0;
        v[0]=0;
        for(int i=0;i<n;i++){
            int val=s[i]-'0';
            val=(1<<val);
            x^=val;
                if(x==0)
                ans=max(ans,i+1);
                else
               {
                  if(v[x]!=0)
                 ans=max(ans,i+1-v[x]);

                int temp=x;
                for(int j=0;j<10;j++){
                    temp=x^(1<<j);
                    if(temp==0)
                        ans=max(ans,i+1);
                    if(v[temp]!=0){
                        ans=max(ans,i+1-v[temp]);
                    }
                    
                }
                }
            
            if(v[x]==0)
            v[x]=i+1;
        }
       
        return ans;
    }
};
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