152. Maximum Product Subarray | LeetCode

 152. Maximum Product Subarray

Given an integer array nums, find a contiguous non-empty subarray within the array that has the largest product, and return the product.

It is guaranteed that the answer will fit in a 32-bit integer.

A subarray is a contiguous subsequence of the array.

 

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 prefix or suffix of nums is guaranteed to fit in a 32-bit integer.

The solution to the above problem is 

class Solution {

public:

    int maxProduct(vector<int>& nums) {

        int ans=INT_MIN;

        int temp=1;

        for(int i=0; i<nums.size(); i++){

            if(nums[i]!=0){

                temp*=nums[i];

                ans=max(ans,temp);

            }

            else{

                temp=0;

                ans=max(ans,temp);

                temp=1;

            }

            

        }

        temp=1;

        for(int i=nums.size()-1; i>=0; i--){

           if(nums[i]!=0){

                temp*=nums[i];

                ans=max(ans,temp);

            }

            else{

                temp=0;

                ans=max(ans,temp);

                temp=1;

            }

        }

        return ans;

    }

};