Inserting elements into 2D vector

Question

so I\'m creating a class that implements an adjacency list. Currently in my class definition I initialized two vectors:

vector> adjLi         


        

Answer 1

If initially you do not have any values in the vector - You can push values into one vector and then push this vector into the 2D vector. For example:

  vector< vector > vt1;
  vector vt2;

  vt2.push_back(value);
  vt1.push_back(vt2);

If your vector is already populated then -

vt1[index].push_back(value);