How to write Spiral matrix program?

/*************  Creates a spiral matrix square or rectangular .************/

/* It first finds all the indices where items are to be placed. After one iteration of
  the 4 loops, matrix size is reduced. "Start" variable points to the lcation from
  where the filling has to start
*/

typedef struct
{
 int m,n;
}Index;

int Create_Spiral_Matrix ( int Linear[],int Size )
{
 int **Spiral;
 int m = 0 ,n = 0, p = m , q = n, i;
 int c = 0, Start = 0;
 Index *I;

    while ( m*n != Size )
 {
  printf("nFeed in the dimensions of the Spiral Matrix to be formed := ");
  scanf("%d %d",&m,&n);
 }
    p = m;   q = n;
 
 Spiral = (int **) malloc( m * sizeof(int *));   //Check Mem Allocation To Prevent Crash.
 for ( i = 0; i < m; i++)
    Spiral[i] = (int *) malloc( m * sizeof(int));     //Check Mem Allocation To Prevent Crash.

 I = (Index *) malloc(sizeof(Index) * m * n);   //Check Mem Allocation To Prevent Crash.

 while ( c < Size  )
 {
  for ( i = Start; i < n; i++,c++)
  {
   I[c].m = Start;
   I[c].n = i;
  }
  for ( i = Start+1; i < m; i++,c++)
  {
   I[c].m  = i;
   I[c].n = n-1;
  }
  for ( i = n-2; i >= Start; i--,c++)
  {
   I[c].m = m-1;
   I[c].n = i;
  }
  for ( i = m-2; i >= Start+1; i--,c++)
  {
   I[c].m = i;
   I[c].n = Start;
  }

  m --;  n --;     
  Start++;

        if ( m-1 == Start )
  {
   if ( m > n )
    for ( i = Start; i < n; i++,c++)
    {
     I[c].m = Start; 
     I[c].n = n - Start;
    }
   if ( n < m )
    for ( i = Start; i < m; i++,c++)
    {
     I[c].m = Start; 
     I[c].n = n - Start;
    }
  }
 }

 i = 0;
 for (  m = 0; m < p ; m++,printf("n"))
  for (  n = 0; n < q ; n++)
      Spiral [I[i].m] [I[i].n] = Linear[i++];

 for (  m = 0; m < p ; m++,printf("n"))
  for (  n = 0; n < q ; n++)
   printf("%dt",Spiral[m][n]);
return 0;
}

int main()
{
 int Linear1[] = { 1, 5, 8, 9, 5, 7, 4, 8, 0, 2, 3, 6,
               4, 1, 7, 2, 5, 9, 3, 2, 5, 6, 1, 2,
      5, 7, 3, 8, 5, 3, 6, 1, 2, 4, 9, };
   
 int Linear2[] = { 1, 5, 8, 5, 7, 8, 0, 6, 2,
               4, 1, 7, 2, 9, 3, 1, 2, 9,
      5, 7, 3, 8, 5,  2, 4,  };

 Create_Spiral_Matrix(Linear1, sizeof(Linear1)/4);
 Create_Spiral_Matrix(Linear2, sizeof(Linear2)/4);
 printf("n");
 return 0;
}

/*~~~~~~~~~ Creates square and  rectangular matrices ~~~~~~~~*/
/* Input required is dim of the spiral matrix. Just feed in two factors of the size of array. i.e If Items are 35 then m = 5 n = 7 or m = 7 n = 5 or m = 35 n = 1 or m = 1 n = 35.  If Items are 36 then m = 1/3/4/6/9/12/36  n = 36/12/9/6/4/3/1
*/

typedef struct
{
 int m,n;
}Index;

int Create_Spiral_Matrix ( int Linear[],int Size )
{
 int **Spiral;
 int m = 0 ,n = 0, p = m , q = n, i;
 int c = 0, Start = 0;
 Index *I;

    while ( m*n != Size )
 {
  printf("nFeed in the dimensions of the Spiral Matrix to be formed := ");
  scanf("%d %d",&m,&n);
 }
    p = m;   q = n;
 
 Spiral = (int **) malloc( m * sizeof(int *));   //Check Mem Allocation To Prevent Crash.
 for ( i = 0; i < m; i++)
    Spiral[i] = (int *) malloc( n * sizeof(int));     //Check Mem Allocation To Prevent Crash.

 I = (Index *) malloc(sizeof(Index) * m * n);   //Check Mem Allocation To Prevent Crash.

 while ( c < Size  )
 {
  for ( i = Start; i < n; i++,c++)
  {
   I[c].m = Start;
   I[c].n = i;
  }
  for ( i = Start+1; i < m; i++,c++)
  {
   I[c].m  = i;
   I[c].n = n-1;
  }
  for ( i = n-2; i >= Start; i--,c++)
  {
   I[c].m = m-1;
   I[c].n = i;
  }
  for ( i = m-2; i >= Start+1; i--,c++)
  {
   I[c].m = i;
   I[c].n = Start;
  }

  m --;  n --;     
  Start++;

        if ( m-1 == Start )
  {
   if ( m > n )
    for ( i = Start; i < n; i++,c++)
    {
     I[c].m = Start; 
     I[c].n = n - Start;
    }
   if ( n < m )
    for ( i = Start; i < m; i++,c++)
    {
     I[c].m = Start; 
     I[c].n = n - Start;
    }
  }
 }

 i = 0;
 for (  m = 0; m < p ; m++,printf("n"))
  for (  n = 0; n < q ; n++)
      Spiral [I[i].m] [I[i].n] = Linear[i++];

 for (  m = 0; m < p ; m++,printf("n"))
  for (  n = 0; n < q ; n++)
   printf("%dt",Spiral[m][n]);
return 0;
}

int main()
{
 int Linear1[] = { 1, 5, 8, 9, 5, 7, 4, 8, 0, 2, 3, 6,
                4, 1, 7, 2, 5, 9, 3, 2, 5, 6, 1, 2,
       5, 7, 3, 8, 5, 3, 6, 1, 2, 4, 9 };
   
 int Linear2[] = { 1, 5, 8, 5, 7, 8, 0, 6, 2,
                4, 1, 7, 2, 9, 3, 1, 2, 9,
       5, 7, 3, 8, 5,  2, 4  };

 Create_Spiral_Matrix(Linear1, sizeof(Linear1)/4);
 Create_Spiral_Matrix(Linear2, sizeof(Linear2)/4);
 printf("n");
 return 0;
}

Code
#include<stdio.h>
main()
{
int a[20][20],i,j,n,m,p,q,k=0;
printf("
 Enter Order Of matrix");
scanf("%d%d",&m,&n);
for(i=1;i<=m;i++)
for(j=1;j<=n;j++)
    scanf("%d",&a[i][j]);
 
p=m;
q=n;
i=j=1;
 
while(k<p*q)
{
    for(;j<=n&&k<p*q;j++)
    {
        printf("%d ",a[i][j]);
        k++;
    }
    j--;  
    i++;
    for(;i<=m && k<p*q;i++)
    {
        printf("%d ",a[i][j]);
        k++;
    }
    i--;
    j--;    
    for(;j>=i-m+1 && k<p*q;j--)
    {
        printf("%d ",a[i][j]);
        k++;
    }    
    j++;
    i--;
    for(;i>1 && k<p*q;i--)
    {
        printf("%d ",a[i][j]);
        k++;
    }
    if(k<p*q)
    {
        j++;
        i++;
        n--;
        m--;
    }
}
}