Leetcode 238. Product of Array Except Self

採用動態規劃的思想

class Solution {
public:
    vector<int> productExceptSelf(vector<int>& nums) {
        vector<int>re(nums.size(),1);
        vector<int>left(re);
        int right=1;
        for(int i=1; i<nums.size(); ++i)
        {
            left[i]=left[i-1]*nums[i-1];
        }
        for(int i=nums.size()-2; i>=0; --i)
        {
            right*= nums[i+1];
            re[i]=left[i]* right;
        }
        re.back()=left.back();
        return re;
    }
};