<p>The <strong>variance</strong> of a string is defined as the largest difference between the number of occurrences of <strong>any</strong> <code>2</code> characters present in the string. Note the two characters may or may not be the same.</p>

<p>Given a string <code>s</code> consisting of lowercase English letters only, return <em>the <strong>largest variance</strong> possible among all <strong>substrings</strong> of</em> <code>s</code>.</p>

<p>A <strong>substring</strong> is a contiguous sequence of characters within a string.</p>

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

<pre>
<strong>Input:</strong> s = &quot;aababbb&quot;
<strong>Output:</strong> 3
<strong>Explanation:</strong>
All possible variances along with their respective substrings are listed below:
- Variance 0 for substrings &quot;a&quot;, &quot;aa&quot;, &quot;ab&quot;, &quot;abab&quot;, &quot;aababb&quot;, &quot;ba&quot;, &quot;b&quot;, &quot;bb&quot;, and &quot;bbb&quot;.
- Variance 1 for substrings &quot;aab&quot;, &quot;aba&quot;, &quot;abb&quot;, &quot;aabab&quot;, &quot;ababb&quot;, &quot;aababbb&quot;, and &quot;bab&quot;.
- Variance 2 for substrings &quot;aaba&quot;, &quot;ababbb&quot;, &quot;abbb&quot;, and &quot;babb&quot;.
- Variance 3 for substring &quot;babbb&quot;.
Since the largest possible variance is 3, we return it.
</pre>

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

<pre>
<strong>Input:</strong> s = &quot;abcde&quot;
<strong>Output:</strong> 0
<strong>Explanation:</strong>
No letter occurs more than once in s, so the variance of every substring is 0.
</pre>

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

<ul>
	<li><code>1 &lt;= s.length &lt;= 10<sup>4</sup></code></li>
	<li><code>s</code> consists of lowercase English letters.</li>
</ul>

from itertools import combinations

class Solution:
    def largestVariance(self, s: str) -> int:
        #create the pairs of characters to check
        #define maxvariance
        pairs = self.createPairs(list(set(s)))
        maxVar = 0
        
        for i in range(2):
            if i % 2 == 1:
                s = s[::-1]
            
            for f1,f2 in pairs:
                f1Sum,f2Sum = 0,0
                for l in s:
                    if l == f1:
                        f1Sum += 1
                    elif l == f2:
                        f2Sum += 1
                    
                    if f2Sum > 0:
                        var = f1Sum-f2Sum
                        if var < 0:
                            f1Sum,f2Sum = 0,0
                        maxVar = max(maxVar,var)
                        
        return maxVar
        
        #go forward
            #go through pairs
            #define one as f1 and other as f2
            
            #loop through s
                #if f1,
                    #count f1
                #if f2,
                    #count f2
                    
                #calculate variance v f1-f2
                    #if 0,
                        #reset f1,f2
                
                #check max
        
    #find pairs
    
    def createPairs(self, options):
        pairs = []
        for i in range(len(options)):
            for j in range(i + 1, len(options)):
                pairs.append((options[i], options[j]))
                pairs.append((options[j], options[i]))  # Include both orderings
        return pairs
8186