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.

 1 public class Solution {
 2     public int maxProduct(int[] A) {
 3         if (A==null || A.length==0) return 0;
 4         int max_local = A[0];
 5         int min_local = A[0];
 6         int global = A[0];
 7         for (int i=1; i<A.length; i++) {
 8             int max_copy = max_local;
 9             max_local = Math.max(Math.max(max_local*A[i], A[i]), min_local*A[i]);
10             min_local = Math.min(Math.min(max_copy*A[i], A[i]), min_local*A[i]);
11             global = Math.max(max_local, global);
12         }
13         return global;
14     }
15 }