<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>

class Solution:
    def largestVariance(self, s: str) -> int:
        
        char_set = list(set(s))
        char_count = dict()
        for i in s:
            if i not in char_count:
                char_count[i] = 0
            char_count[i] += 1
        # a b c d
        # abcd
        # 0 1 2 3
        # aabbcdde

        # aabbcdde
        # aaaaa
        largest_var = 0
        for i in range(0, len(char_set)):
            for j in range(0, len(char_set)):
                if i == j:
                    continue
                i_count, j_count = 0, 0
                j_bef_i = False
                j_remain_count = char_count[char_set[j]]
                for k in range(len(s)):
                    if s[k] == char_set[i]:
                        i_count += 1
                    elif char_set[j] == s[k]:
                        j_count += 1
                        j_remain_count -= 1
                    if j_count > 0:
                        largest_var = max(largest_var, i_count - j_count)
                    if i_count < j_count and j_remain_count > 0:
                        i_count = 0
                        j_count = 0
        return largest_var
5768