initialize 2d vector

1auto M = 4;	// num of rows
2auto N = 3; // num of cols in each row
3auto default_value = 1; // default value of all int elements
4std::vector<std::vector<int>> matrix(M, std::vector<int>(N, default_value));

1vector<vector<int> > vec( n , vector<int> (m, 0));

1// Initializing 2D vector "vect" with 
2// values 
3vector<vector<int> > vect{ { 1, 2, 3 }, 
4                           { 4, 5, 6 }, 
5                           { 7, 8, 9 } }; 

1vector<vector<int> >    v2(8, vector<int>(5));
2

1std::vector<vector<int>> d;
2//std::vector<int> d;
3cout<<"Enter the N number of ship and port:"<<endl;
4cin>>in;
5cout<<"\Enter preference etc..:\n";
6for(i=0; i<in; i++){ 
7cout<<"ship"<<i+1<<":"<<' ';
8    for(j=0; j<in; j++){
9    cin>>temp;
10    d.push_back(temp);// I don't know how to push_back here!!
11    }
12}