152. Maximum Product Subarray

class Solution {public:    int maxProduct(vector<int>& nums) {     if(nums.size()==0)        return 0;     int minpre=1;     int maxpre=1;     int maxhere;//以a[i]结尾的乘积最大值     int minhere;//以a[i]结尾的乘积最小值     int maxsofar=INT_MIN;     for(int i=0;i<nums.size();i++)     {         maxhere=max(max(maxpre*nums[i],minpre*nums[i]),nums[i]);         minhere=min(min(maxpre*nums[i],minpre*nums[i]),nums[i]);         maxsofar=max(maxhere,maxsofar);         maxpre=maxhere;         minpre=minhere;     }     return maxsofar;    }};