<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:
        return max(self.get_side(nums), self.get_side(nums[::-1]))

    def get_side(self, nums):
        res, s, cur = 0, -1, 0
        neg_list = [0] * len(nums)
        for i, ele in enumerate(nums):
            if i == 0:
                if ele == 0: val = 0
                elif ele > 0: val = 1
                else: val = - 1
                neg_list[i] = val
            else:
                if neg_list[i-1] != 0:
                    if ele == 0: val = 0
                    elif ele > 0: val = 1
                    else: val = -1
                    neg_list[i] = neg_list[i-1]*val 
                else:
                    if ele == 0: val = 0
                    elif ele > 0: val = 1
                    else: val = -1
                    neg_list[i] = val       
        # print(neg_list)
        for i, ele in enumerate(neg_list):
            if ele == 1:
                cur += i - s
                s = i
                #print(i, ele, s, cur, res)
                res = max(cur, res)
            elif ele == 0:
                cur = 0
                s = i
                #print("-", i, ele, s, cur, res)

        #print(res)
        return res

                





        
549