<p>You wrote down many <strong>positive</strong> integers in a string called <code>num</code>. However, you realized that you forgot to add commas to seperate the different numbers. You remember that the list of integers was <strong>non-decreasing</strong> and that <strong>no</strong> integer had leading zeros.</p>

<p>Return <em>the <strong>number of possible lists of integers</strong> that you could have written down to get the string </em><code>num</code>. Since the answer may be 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> num = &quot;327&quot;
<strong>Output:</strong> 2
<strong>Explanation:</strong> You could have written down the numbers:
3, 27
327
</pre>

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

<pre>
<strong>Input:</strong> num = &quot;094&quot;
<strong>Output:</strong> 0
<strong>Explanation:</strong> No numbers can have leading zeros and all numbers must be positive.
</pre>

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

<pre>
<strong>Input:</strong> num = &quot;0&quot;
<strong>Output:</strong> 0
<strong>Explanation:</strong> No numbers can have leading zeros and all numbers must be positive.
</pre>

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

<ul>
	<li><code>1 &lt;= num.length &lt;= 3500</code></li>
	<li><code>num</code> consists of digits <code>&#39;0&#39;</code> through <code>&#39;9&#39;</code>.</li>
</ul>

MOD = 1000000007

class Solution:
    def numberOfCombinations(self, num: str) -> int:
        n = len(num)
        a = [[0] * n for _ in range(n)]
        b = [[0] * n for _ in range(n)]
        
        for i in range(n - 1, -1, -1):
            if num[i] == '0':
                continue
            
            for j in range(n - 1, i - 1, -1):
                if j == n - 1:
                    a[i][j] = 1
                else:
                    length = j - i + 1
                    first = j + 1
                    last = first + length
                    cnt = 0
                    
                    if last <= n and num[i:i+length] <= num[first:first+length]:
                        cnt = (cnt + a[first][last - 1]) % MOD
                    
                    if last < n:
                        cnt = (cnt + b[first][last]) % MOD
                    
                    a[i][j] = cnt
                
                b[i][j] = (b[i][j + 1] if j + 1 < n else 0) + a[i][j]
                b[i][j] %= MOD
        
        return b[0][0]

3054