152 Maximum Product Subarray

public class Solution {
   public int maxProduct(int[] A) {
        if (A == null || A.length == 0) {
            return 0;
        }
        if (A.length == 1) {
            return A[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_copy = 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_copy*A[i]), A[i] * min_local);
            global = Math.max(global, max_local);
        }
        return global;
    }
}

参考 http://blog.csdn.net/linhuanmars/article/details/39537283

全局最优和局部最优，只是这里局部最优要考虑局部最大和局部最小， 因为有负数相乘。