<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 arr[1<<10];
        for(int i=0;i<(1<<10);i++)
        arr[i]=INT_MAX;
        int mx=0;

        // find exact state 
        // toggle each idx and find state

        arr[0]=-1;
        int state=0;

        for(int i=0;i<s.length();i++)
        {
            int mask=(1<<(s[i]-'0'));
             state=(state^mask);

if(arr[state]!=INT_MAX)
mx=max(mx,i-arr[state]);

for(int odd=9;odd>=0;odd--)
{
    mask=(1<<odd);
    if(arr[(state^mask)]!=INT_MAX)
    mx=max(mx,i-arr[(state^mask)]);

}
if(arr[state]==INT_MAX)
arr[state]=i;
        }

        return mx;
    }
};
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