lintcode-medium-Maximum Product Subarray

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

 

Example

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

 

public class Solution {
    /**
     * @param nums: an array of integers
     * @return: an integer
     */
    public int maxProduct(int[] nums) {
        // write your code here
        
        if(nums == null || nums.length == 0)
            return 0;
        
        int size = nums.length;
        
        int[] max = new int[size];
        int[] min = new int[size];
        int result = nums[0];
        max[0] = nums[0];
        min[0] = nums[0];
        
        for(int i = 1; i < size; i++){
            max[i] = Math.max(Math.max(min[i - 1] * nums[i], nums[i]), max[i - 1] * nums[i]);
            min[i] = Math.min(Math.min(max[i - 1] * nums[i], nums[i]), min[i - 1] * nums[i]);
            result = Math.max(result, max[i]);
        }
        
        return result;
    }
}