I wanted to know if I can make the matrix size entered by the user dynamic. Currently I have fixed it as a 2*2 matrix. If I try making it a dynamic array it says the integer should be constant.

```
#include<iostream>
#include<iomanip>
using namespace std;
int input ();
void output(int [][2], int, int );
void add ( int [][2],int [][2], int, int );
void sub (int [][2],int [][2], int , int );
void multi (int [][2], int [][2], int, int);
void trans (int [2][2], int , int );
const int r=2, c=2;
int a[r][c],b[r][c];
int main ()
{
int A;
cout<<"enter your choice 1.Add, 2. Sub 3. Multi 4.trans \n";
cin>>A;
input();
switch (A)
{
case 1:
add ( a, b, r, c);
break;
case 2:
sub (a, b, r, c);
break;
case 3:
multi (a, b, r, c);
break;
case 4:
trans (a,r,c);
break;
default:
cout<<"wrong choice \n";
break; }
return 0;
}
int input ()
{ cout<<"Enter matrix 1 \n";
for (int i=0; i<r; i++)
for (int j=0; j<c; j++)
{
cin>>a[i][j];
}
cout<<"your matrix 1 \n";
output(a,r,c);
cout<<"enter matrix 2 \n";
for (int i=0; i<r; i++)
for (int j=0; j<c; j++)
{
cin>>b[i][j];
}
cout<<"your matrix 2 \n";
output (b,r,c);
return (a[r][c], b[r][c]);
}
void output (int g [r][c], int r, int c)
{
for (int i=0; i<r; i++)
{
for (int j=0; j<c; j++)
{ cout<<setw(10)<<g[i][j];
}
cout<<endl;
}
}
void add (int a[r][c],int b[r][c], int r, int c)
{ int i=0,j=0;
int g[2][2];
for (int i=0;i<r;i++)
{
for (int j=0;j<c;j++)
g[i][j] = a[i][j] + b[i][j];
}
cout<<"your answer is \n";
output (g,r,c);
}
void sub (int a[r][c], int b[r][c], int r, int c)
{
int i=0,j=0;
int g[2][2];
for (int i=0;i<r;i++)
{
for (int j=0;j<c;j++)
g[i][j] = a[i][j] - b[i][j];
}
cout<<"your answer is \n";
output (g,r,c);
}
void multi (int a[2][2], int [2][2], int r, int c)
{ int g[2][2] = {};
for (int i=0; i<r; i++)
for (int j=0; j<c; j++)
for (int k=0;k<r;k++)
{
g[i][j] += a[i][k] * a[k][j];
}
cout<<"the answer is \n";
output (g,r,c);
}
void trans (int a[r][c], int r, int c)
{
int g[2][2]={};
for (int i=0; i<r;i++)
for (int j=0; j<c;j++)
{
g[i][j]=a[j][i];
}
cout<<"the ans is : \n";
output (g,r,c);
}
```