// jagged array demonstration
// Mikhail Nesterenko
// 11/29/2016

#include <iostream>
#include <vector>

using std::cin; using std::cout; using std::endl;
using std::vector;

 
int main (){
   vector <int> row;
   vector<vector<int>> a;

   // populating table with continously increasing rows
   for(int i=0; i < 4; ++i) {
     row.push_back(i);
     a.push_back(row);
   }

   // printing the table
   for (int i=0; i < a.size(); ++i){
      for (int j=0; j < a[i].size(); ++j)
	 cout << a[i][j] << " ";
      cout << endl;
   } 

   cout << endl;

   // removing middle row
   a.erase(a.begin()+1);
   
   // adding element to a middle row
   a[2].insert(a[2].begin()+1, 55);

   // printing resulting table
   for (int i=0; i < a.size(); ++i){
      for (int j=0; j < a[i].size(); ++j)
	 cout << a[i][j] << " ";
      cout << endl;
   } 

}