[LeetCode] Maximum Product Subarray

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：参考http://blog.csdn.net/worldwindjp/article/details/39826823

class Solution {
public:
    int maxProduct(vector<int>& nums) {
    if (nums.empty()) return 0;

    int max_product = nums[0];
    int max_pre = nums[0];
    int min_pre = nums[0];

    for (auto iter = nums.begin() + 1; iter != nums.end(); ++iter) {
        int max_temp = max_pre * (*iter);
        int min_temp = min_pre * (*iter);

        max_pre = max(max(max_temp, min_temp), (*iter));
        min_pre = min(min(max_temp, min_temp), (*iter));
        max_product = max(max_pre, max_product);
    }

    return max_product;
}
};