/*
** symmetry.c: A symmetry checker for 2D arrays 
**       written by Jeff Tian
**       Nov. 20, 1997
*/

#include <stdio.h>
#include <stdlib.h>

void prt_matrix(int matrix[][10], int);

main(void)
{
   int i, j, A[10][10], B[10][10]={{1,2}, {3,4}}, I[10][10];
 
   for (i=0; i<=9; i++) 
      for (j=0; j<=9; j++) 
      {
         I[i][j]=0; 
         A[i][j]=i*j;
      }
   for (i=0; i<=9; i++) I[i][i]=1; 

   printf("==============================================\n");
   printf("Matrix  Symmetry (1=symmetric/0=not symmetric)\n");
   printf("==============================================\n");
   printf("   A        %d\n", symmetry(A, 10));
   printf("   B        %d\n", symmetry(B, 2));
   printf("   I        %d\n", symmetry(I, 10));
   printf("==============================================\n");
   printf("\nWhere matrix A is as follows:\n");
   prt_matrix(A, 10);
   printf("\nWhere matrix B is as follows:\n");
   prt_matrix(B, 2);
   printf("\nWhere matrix I is as follows:\n");
   prt_matrix(I, 10);

   exit(0);
}

/*
** symmetry()
**    Check a square matrix to see if it is a symmetric
*/

symmetry(int matrix[][10], int n)
{
   int i, j, result=1;

   if (n > 1)
   {
      for(i=0; i<n && result; i++)
      {
         for(j=0; j<i && result; j++)
            if (matrix[i][j] != matrix[j][i])
               result = 0;
      }
   }
   return result;
}

/*
** prt_matrix()
**    Print a matrix 
*/

void prt_matrix(int matrix[][10], int n)
{
   int i, j;

   if (n > 0)
   {
      for(i=0; i<n; i++)
      {
         for(j=0; j<n; j++)
            printf("%3d", matrix[i][j]);
         printf("\n");
      }
   }
   return;
}