How to delete from 2D array?

Question

I have this vector in an external file

1 4 12 3
13 3 22 5
14 22 2 34
222 11 3 31

and I want to delete x column and y row. How can I do it and print it in an external file?

It's a 2D vector with 4 rows and columns with 4elements.

#include<iostream>
#include<fstream>

using namespace std;

void main ()
{
    int a[100][100],m,n;
    ifstream f("mat.txt");
    ofstream b("out.txt");
    f>>n;

    for(int i=0; i<n; i++)
    {
        for(int j=0; j<n; j++)
        {
            f>>a[i][j];
        }
    }

    for(int i=0; i<n; i++)
    {
        for(int j=0; j<n; j++)
        {
            b<<a[i][j]<<" ";
        }
        b<<endl;
    }
}

Answer 1

In this example, I've hardcoded values of x, y, and the file names.

#include <iostream>
#include <fstream>
using namespace std;

int main() {
  ifstream fin("in.txt");
  ofstream fout("out.txt");
  int i, j, x = 1, y = 2;
  if (fin.is_open() && fout.is_open()) {
    for (i = 0; i < 16; ++i) {
      fin >> j;
      if (i % 4 != x && i / 4 != y) {
        fout << j;
        if (i % 4 == 3) {
          fout << endl;
        } else {
          fout << " ";
        }
      }
    }
    fin.close();
    fout.close();
  }
  return 0;
}

Answer 2

Probably you need to use some container instead of a plain 2d array in case of pushing and poping from a middle of it. Try to use this http://i.stack.imgur.com/G70oT.png for picking up right or search images by keywords std,container,choose.