<p>Given an array of integers <code>nums</code>, find the maximum length of a subarray where the product of all its elements is positive.</p>

<p>A subarray of an array is a consecutive sequence of zero or more values taken out of that array.</p>

<p>Return <em>the maximum length of a subarray with positive product</em>.</p>

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

<pre>
<strong>Input:</strong> nums = [1,-2,-3,4]
<strong>Output:</strong> 4
<strong>Explanation:</strong> The array nums already has a positive product of 24.
</pre>

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

<pre>
<strong>Input:</strong> nums = [0,1,-2,-3,-4]
<strong>Output:</strong> 3
<strong>Explanation:</strong> The longest subarray with positive product is [1,-2,-3] which has a product of 6.
Notice that we cannot include 0 in the subarray since that&#39;ll make the product 0 which is not positive.</pre>

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

<pre>
<strong>Input:</strong> nums = [-1,-2,-3,0,1]
<strong>Output:</strong> 2
<strong>Explanation:</strong> The longest subarray with positive product is [-1,-2] or [-2,-3].
</pre>

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

<ul>
	<li><code>1 &lt;= nums.length &lt;= 10<sup>5</sup></code></li>
	<li><code>-10<sup>9</sup> &lt;= nums[i] &lt;= 10<sup>9</sup></code></li>
</ul>

class Solution:
    def getMaxLen(self, nums: List[int]) -> int:
        n = len(nums)
        # pos[i]", "neg[i]" represent longest consecutive numbers ending with nums[i] forming a positive/negative product.
        pos, neg = [0] * n, [0] * n

        # Base case
        if nums[0] > 0: 
            pos[0] = 1
        if nums[0] < 0: 
            neg[0] = 1

        ans = pos[0]
        for i in range(1, n):
            if nums[i] > 0:
                pos[i] = 1 + pos[i-1]
                neg[i] = 1 + neg[i-1] if neg[i - 1] > 0 else 0 # It still negative
            elif nums[i] < 0:
                pos[i] = 1 + neg[i-1] if neg[i - 1] > 0 else 0 # It turn positive
                neg[i] = 1 + pos[i-1] # It turn negatuve
            ans = max(ans, pos[i])
        return ans
494