<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:
        positive = 0
        negative = 0
        res = 0
        for n in nums:
            if n == 0:
                positive = 0
                negative = 0
            elif n > 0:
                positive += 1
                negative = negative + 1 if negative > 0 else 0
            else:
                #Swap positive_length and negative_length since multiplying by a negative 
                #number flips the sign of the product.
                #Increment negative_length by 1 (since multiplying a negative product by
                # a negative number makes it positive), and if positive_length is greater
                # than 0, increment positive_length
                new_positive = negative + 1 if negative > 0 else 0
                negative = positive + 1
                positive = new_positive

            res = max(res, positive)
        
        return res
30600