User Selected Columns of 2D Array in C++

I think you are looking for dynamic multi-dimensional arrays. Googlefu should help, leads to this article:

http://www.cplusplus.com/forum/beginner/63/

Look near the bottom.

You provided us a little information, I guess you are asking for a C++ code that first takes column number from user and then calculates rows on the basis of formula and finally creates a two dimensional array, right ?
Formula given : rows = 3^columns.

I've written a C++ code for you

I've tested this code on my linux( ubuntu ) platform , I hope this is what you are asking.

#include <iostream>
#include<math.h>
#define kary 3 // Your k-ary truth table - 3 for ternary truth table(0,1,2), 2 for binary truth table(1,2)

using namespace std;
int main()
{
    int rows,cols,i,j;  // Variable declaration
    cout<<"\n Enter required number of columns =  ";
    cin>>cols;
    rows = pow(kary,cols);
    cout<<"\n Calculated number of rows =  "<<rows;
    int arr[rows][cols]; // Array declaration
    for (i=0; i<rows; i++)
    {
        for (j=0; j<cols; j++)
           arr[i][j]=((i/(int) pow(kary, j)) % kary); //logic
    }
    cout<<"\n Your array holds this data \n";
    for(i = 0; i < rows; i++)
    {
        for (j=cols-1; j>=0; j--)
            cout<<"\t"<<arr[i][j];
        cout<<"\n";
    }
    return 0;
}