What is the output of the following code? int main() { vector nums; int i = 0; } nums.push_back(4); nums.push_back(3); nums.push_back(2); nums.push_back(1); nums.erase(nums.begin() + 0); for(i = 0; i < nums.size(); ++i) { cout < < nums.at(i) < < " "; } return 0;