1. 238

product-of-array-except-self

2. 算法

http://www.tuicool.com/articles/IbUvmeJ

http://www.cnblogs.com/grandyang/p/4650187.html

• O(n)

3. 代码

class Solution{
public:
    vector<int>  productExceptSelf(vector<int>& nums){
        vector<int> res(nums.size(),1);
        for(int i=1;i<nums.size();++i)
            res[i]=res[i-1]*nums[i-1];
        int right=1;
        for(int i=nums.size()-1;i>=0;--i){
            res[i]*=right;
            right*=nums[i];
        }
        return res;
    }
};