Maximum Product Subarray

Given an integer array `nums`, find a subarray that has the largest product, and return _the product_. The test cases are generated so that the answer will fit in a **32-bit** integer.   **Example 1:** **Input:** nums = [2,3,-2,4] **Output:** 6 **Explanation:** [2,3] has the largest product 6. ``` **Example 2:** **Input:** nums = [-2,0,-1] **Output:** 0 **Explanation:** The result cannot be 2, because [-2,-1] is not a subarray. ```   **Constraints:** - `1 <= nums.length <= 2 * 104` - `-10 <= nums[i] <= 10` - The product of any subarray of `nums` is **guaranteed** to fit in a **32-bit** integer.