152 Maximum Product Subarray.java

// 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.

class Solution {
    public int maxProduct(int[] nums) {
        int prefix = 1, suffix = 1, max = -11;

        for(int i = 0; i< nums.length;i++){
            prefix *= nums[i];
            suffix *= nums[nums.length -i-1];

            max = Math.max(max, Math.max(suffix, prefix));
            
            prefix = (prefix == 0)?1:prefix;
            suffix = (suffix == 0)?1:suffix;
        }
        return max;
    }
}