LeetCode-Maximum Product Subarray

Find the contiguous subarray within an array (containing at least one number) which has the largest product.

For example, given the array [2,3,-2,4],
the contiguous subarray [2,3] has the largest product = 6.

Solution:

Code:

<span style="font-size:14px;">class Solution {
public:
    int maxProduct(int A[], int n) {
        int maxPos, minNeg, prePositive = 0, preNegative = 0, positive, negative;
        bool pos = false;
        if (A[0] < 0) {
            preNegative = A[0];
            minNeg = A[0];
            maxPos = INT_MIN;
        }
        else {
            pos = true;
            prePositive = A[0];
            maxPos = A[0];
            minNeg = INT_MIN;
        }
        for (int i = 1; i < n; ++i) {
            if (A[i] > 0) {
                pos = true;
                positive = max(prePositive*A[i], A[i]);
                negative = min(preNegative*A[i], A[i]);
            } else if (A[i] < 0) {
                positive = max(preNegative*A[i], A[i]);
                negative = min(prePositive*A[i], A[i]);
            } else {
                positive = 0;
                negative = 0;
            }
            if (positive > 0) pos = true;
            maxPos = max(maxPos, positive);
            minNeg = max(minNeg, negative);
            prePositive = positive;
            preNegative = negative;
        }
        if (pos) return maxPos;
        else return minNeg;
    }
};</span>