剑指offer-构建乘积数组

class Solution {
public:
    vector<int> multiply(const vector<int>& A) {
        int len = A.size();
        vector<int> B(len);
        for(int i=0;i<len;i++){
            int sum = 1;
            for(int j=0;j<len;j++){
                if(j!=i){
                    sum*=A[j];
                }
            }
            B[i] = sum;
        }
        return B;
    
    }
};