238. Product of Array Except Self除自身以外数组的乘积

参考：https://leetcode.com/problems/product-of-array-except-self/discuss/65622/Simple-Java-solution-in-O(n)-without-extra-space

class Solution {
public:
    vector<int> productExceptSelf(vector<int>& nums) {
        vector<int> res(nums.size(),1);
        int right = 1;

        for(int i=1;i<nums.size();i++)
        {
            res[i] = res[i-1] * nums[i-1];
        }

        for(int i=nums.size()-1;i>=0;i--)
        {
            res[i] *= right;
            right *= nums[i];
        }
        return res;
    }
};