<p>Given a binary string <code>s</code>, you can split <code>s</code> into 3 <strong>non-empty</strong> strings <code>s1</code>, <code>s2</code>, and <code>s3</code> where <code>s1 + s2 + s3 = s</code>.</p>

<p>Return the number of ways <code>s</code> can be split such that the number of ones is the same in <code>s1</code>, <code>s2</code>, and <code>s3</code>. Since the answer may be too large, return it <strong>modulo</strong> <code>10<sup>9</sup> + 7</code>.</p>

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

<pre>
<strong>Input:</strong> s = &quot;10101&quot;
<strong>Output:</strong> 4
<strong>Explanation:</strong> There are four ways to split s in 3 parts where each part contain the same number of letters &#39;1&#39;.
&quot;1|010|1&quot;
&quot;1|01|01&quot;
&quot;10|10|1&quot;
&quot;10|1|01&quot;
</pre>

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

<pre>
<strong>Input:</strong> s = &quot;1001&quot;
<strong>Output:</strong> 0
</pre>

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

<pre>
<strong>Input:</strong> s = &quot;0000&quot;
<strong>Output:</strong> 3
<strong>Explanation:</strong> There are three ways to split s in 3 parts.
&quot;0|0|00&quot;
&quot;0|00|0&quot;
&quot;00|0|0&quot;
</pre>

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

<ul>
	<li><code>3 &lt;= s.length &lt;= 10<sup>5</sup></code></li>
	<li><code>s[i]</code> is either <code>&#39;0&#39;</code> or <code>&#39;1&#39;</code>.</li>
</ul>

class Solution:
    def numWays(self, s: str) -> int:
        MOD = 10**9 + 7
        s = [int(x) for x in list(s)]
        cur_sum = sum(s)

        if cur_sum == 0:
            return (len(s) - 1) * (len(s) - 2) // 2 % MOD

        if cur_sum % 3 != 0:
            return 0

        target = cur_sum / 3

        smallest_prefix = 0
        largest_prefix = 0

        cur = 0
        if cur == target:
            smallest_prefix = 1

        for i in range(len(s)):
            char = s[i]
            if char == 1:
                cur += 1
                if cur == target:
                    if smallest_prefix == 0:
                        smallest_prefix = i + 1
                if cur == target + 1:
                    largest_prefix = i + 1

        smallest_suffix = 0
        largest_suffix = 0

        cur = 0

        if cur == target:
            smallest_suffix = 1
        for i in range(len(s) -1, -1, -1):
            char = s[i]
            if char == 1:
                cur += 1
                if cur == target:
                    if smallest_suffix == 0:
                        smallest_suffix = len(s) - i + 1
                if cur == target + 1:
                    largest_suffix = len(s) - i + 1

        diff1 = largest_prefix - smallest_prefix
        diff2 = largest_suffix - smallest_suffix

        return (diff1 * diff2) % MOD
                
    
19300