Maximum Product subarray

Change-Id: I90e90631a47fc030d5e1996f1c2bd611e0d92bc1

Author: applewjg

MaximumProductSubarray.java

@@ -0,0 +1,28 @@
+/*
+ Author:     King, [email protected]
+ Date:       Oct 06, 2014
+ Problem:    Maximum Product Subarray
+ Difficulty: Medium
+ Source:     https://oj.leetcode.com/problems/maximum-product-subarray/
+ Notes:
+ 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 {
+    public int maxProduct(int[] A) {
+        if (A.length <= 0) {
+            return 0;
+        }
+        int maxVal = A[0], minVal = A[0], res = A[0];
+        for (int i = 1; i < A.length; ++i) {
+            int tmpVal = maxVal;
+            maxVal = Math.max(Math.max(maxVal * A[i], minVal * A[i]), A[i]);
+            minVal = Math.min(Math.min(tmpVal * A[i], minVal * A[i]), A[i]);
+            res = Math.max(res, maxVal);
+        }
+        return res;  
+    }
+}