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.

[分析]

记录当前最大, 最小值. 因为遇到负数时, 与最小值的product可能成为最大值.

[注意事项]
注意0值的处理.

[CODE]

public class Solution {
    public int maxProduct(int[] A) {
        if(A==null || A.length<1) return 0;
        if(A.length < 2) return A[0];

        int global = A[0];
        int max = A[0], min = A[0];
        for(int i=1; i<A.length; i++) {
            int a = max*A[i];
            int b = min*A[i];
            
            max = Math.max(A[i], Math.max(a, b));
            min = Math.min(A[i], Math.min(a, b));
            global = Math.max(max, global);
        }
        
        return global;
    }
}

leetcode 152: Maximum Product Subarray