leetcode maximum-product-subarray

https://oj.leetcode.com/problems/maximum-product-subarray/点击打开链接

题目描述：

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.

int a[]; minVal,   maxVal : 是以a[i]为结尾的连续subarray的最大值和最小值。

初始值的设定： minVal = maxVal = a[0];

迭代更新的方法：

for each a[i]  :

temp1 = a[i] * minVal; temp2 = a[i] * maxVal;

maxVal = max(a[i], max(temp1, temp2));  

minVal = min(a[i], min(temp1, temp2));

 int maxProduct(int a[], int n) /* subarray 需要连续 */
    {
        int maxVal = a[0];
        int minVal = a[0];
        int result = a[0];
        if (n == 1)
        {
            return maxVal;
        }
        for (int i = 1; i < n; i++)
        {
            int temp1 = maxVal * a[i];
            int temp2 = minVal * a[i];
            maxVal = max(a[i], max(temp1, temp2));
            minVal = min(a[i], min(temp1, temp2));
            result = max(maxVal, result);
        }
        return result;
    }