/***
 * 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.
 */
public class Solution {
    // Solution 1: O() 
    public int maxProduct(int[] A) {
        if (A == null || A.length == 0)
            return 0;
        int max_local = A[0];
        int min_local = A[0];
        int global = A[0];
        for (int i = 1; i < A.length; i++) {
            int max_temp = max_local;
            max_local = Math.max(Math.max(A[i] * max_local, A[i]), A[i] * min_local);
            min_local = Math.min(Math.min(A[i] * max_temp, A[i]), A[i] * min_local);
            global = Math.max(global, max_local);
        }
        return global;
    }
}

add MaximumProductSubarray.java