how to push two elements in vector in c++ code example

Example 1: how to append one vector to another c++

vector<int> a;
vector<int> b;
// Appending the integers of b to the end of a 
a.insert(a.end(), b.begin(), b.end());

Example 2: how to append two vectors in c++

std::vector<int> AB = A;
AB.insert(AB.end(), B.begin(), B.end());