构建乘积数组

class Solution {
public:
    vector<int> multiply(const vector<int>& A) {
        vector<int> result;
        if(A.size() == 0)
            return result;
        
        result.push_back(1);
        int temp = 1;
        for(int i =1;i < A.size(); i++){
            temp*=A[i-1];
            result.push_back(temp);
        }
        
        temp = 1;
        for(int i = A.size()-2;i>=0;i--){
            temp*=A[i+1];
            result[i] *= temp;
        }
        
        return result;
    }
};