how to input in 2d array c++ code example

Example 1: how to take input in 2d vector in c++

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

Example 2: how to print a 2d array in c++

for (int i = 0; i < m; i++) 
{ 
   for (int j = 0; j < n; j++) 
   { 
      cout << arr[i][j] << " "; 
   } 
     
   // Newline for new row 
   cout << endl; 
}