In this program the user enters the # of columns of the matrix and then the entries of the matrix. So, for example, if the user enters 2 for column # and 1 2 3 4 for entries then the program develops a 2 by 2 matrix with 1 2 3 4 as entries. My program works perfectly in such a case. However, if the user for example had only entered 1 2 3 then my program makes a matrix with garbage values. I would like the program in such a case to exit the program.

It is a simple question, but it has me baffled.

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

int  main()
{
  int m,x, n, c = 0, d,k, matrix[10][10], transpose[10][10], product[10][10];

  printf("Enter the number of columns of matrix ");
  scanf("%d",&m);
  if(m<=0){
    printf("You entered a invalid value.");
    exit(0);
  }
  else{
    printf("Enter the elements of matrix \n");

    for( c = 0 ; c < 10 ; c++ )
      {
        for( d = 0 ; d < m ; d++ )
          {
            scanf("%d",&matrix[c][d]);
            if (matrix[c][d] == 99) 
              // 'x' is character variable I declared to use as a break
              break;
            // c = c+1;

          }
        if (matrix[c][d] == 99)
          break;
      }
  }

  printf("\nHere is your matrix:\n");
  int i;

  for(i=0;i<c;i++)
    {
      for(d=0;d<m;d++)
        {
            printf("%3d ",matrix[i][d]);
        }
      printf("\n");
    }