<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 {
public:
    int getMaxLen(vector<int>& nums) {
        std::vector<int> indexesWithZero;
        indexesWithZero.push_back(-1);
        for (int i = 0; i < nums.size(); i += 1) {
            if (nums[i] == 0) {
                indexesWithZero.push_back(i);
            }
        }
        indexesWithZero.push_back(nums.size());
        int best = 0;
        for (int i = 1; i < indexesWithZero.size(); i += 1) {
            int current = getMaxPositiveSubArrayRange(
                indexesWithZero[i - 1] + 1, indexesWithZero[i] - 1, nums);
            best = std::max(best, current);
        }
        return best;
    }

private:
    int getMaxPositiveSubArrayRange(int L, int R, std::vector<int>& v) {
        if (L > R) {
            return 0;
        }
        std::vector<int> indexesWithNegative;
        for (int i = L; i <= R; i += 1) {
            if (v[i] < 0) {
                indexesWithNegative.push_back(i);
            }
        }
        if (!(indexesWithNegative.size() & 1)) {
            return R - L + 1;
        }
        int beginning = indexesWithNegative.back() - L;
        int ending = R - indexesWithNegative.front();
        return std::max(beginning, ending);
    }
};
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