程序代码：

int main()
{   
    vector<int> ivec;
    int ival, sum = 0;
    while(cin >> ival)
        ivec.push_back(ival);
        
    for(int ix = 0; ix < ivec.size(); ++ix)
        
        sum += ivec[ix];
        
    int average = sum / ivec.size();
    
    cout << "sum of " << ivec.size() << " elements: " << sum << ". average: " << average << endl;
    
    return 0;
}