combine two vectors c 2b 2b

1vector1.insert(vector1.end(), vector2.begin(), vector2.end());

1vector<int> v1 = {1, 2, 3}; 
2vector<int> v2 = {4, 5, 6};
3copy(v1.begin(), v1.end(),back_inserter(v2)); 
4// v2 now contains 4 5 6 1 2 3
5

1std::vector<int> AB = A;
2AB.insert(AB.end(), B.begin(), B.end());