<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) {
        unordered_map<int,int> m;
        m[0]=0;
        int n=s.size();
        vector<int> store(n+1,0);
        //int n=s.size();
        int ans=1;
        for(int i=0;i<n;i++){
            int c=s[i]-'0';
            int ind=i+1;
            int pres=store[ind-1];
            pres=pres^(1<<c);

            //cout<<pres<<" ";

            if(m.find(pres)!=NULL) ans=max(ans,ind-m[pres]);
            for(int i=0;i<=9;i++){
                    pres^=(1<<i);
                    if(m.find(pres)!=NULL) { 
                        //cout<<ind<<"*"<<i<<"* ";
                        ans=max(ans,ind-m[pres]);
                    }
                    pres^=(1<<i);
            }

            store[ind]=pres;
            if(m.find(pres)==NULL) m[pres]=ind;
        }
        return ans;
    }
};
16000