Programming Questions

#include<stdio.h>

int main(){

  int a[10][10],i,j,sum=0,m,n;

  printf("\nEnter the row and column of matrix: ");
  scanf("%d %d",&m,&n);

  printf("\nEnter the elements of matrix: ");
  for(i=0;i<m;i++)
      for(j=0;j<n;j++)
           scanf("%d",&a[i][j]);
  printf("\nThe matrix is\n");

  for(i=0;i<m;i++){
      printf("\n");
      for(j=0;j<m;j++){
      printf("%d\t",a[i][j]);
      }
 }
 for(i=0;i<m;i++){
     for(j=0;j<n;j++){
          if(i==j)
              sum=sum+a[i][j];
     }
 }
 printf("\n\nSum of the diagonal elements of a matrix is: %d",sum);

 return 0;
}

Sample output:

Enter the row and column of matrix: 3 3
Enter the elements of matrix:
2
3
5
6
7
9
2
6
7
The matrix is
2       3       5
6       7       9
2       6       7
Sum of the diagonal elements of a matrix is: 16

Yes, using the realloc() function as shown below:

main()

{

        int *p;

        p = ( int *) malloc (20) ;

        t = p;

        t = (int *) realloc ( p, 40);

        if ( t == NULL )

        Printf (" Cannot reallocate, leaves previous allocated region unchanged ");

       else

       {

              if ( p ==t )

              ;  / * the array expanded at the same region */

             else

            { 

                 free ( p ); / * deallocate the original array */

                 p = t;  /* set p to newly allocated region */

             }

      }

}  

for ( i=0; i < MAXROW ; i++)

free (p[i]);

free (p);

When a function accepts a variable number of arguments , its prototype cannot provide any information about the number of arguments and type of those variable arguments. Hence the compiler cannot warn about the mismatches. The programmer must make sure that arguments match or must manually insert explicit typecast.

A is incorrect. It is acceptable to use assertions to test the arguments of private methods.

B is incorrect. While assertion errors can be caught, Sun discourages you from doing so.

struct emp

{

     char n[20];

      int age;

};

main()

{

    struct emp e1 = {"Dravid", 23};

   struct emp e2;

   scanf ("%s %d",e2.n, & e2.age);

   if( structcmp (e1,e2) ==0)

        printf ("The structures are equal");

   else

         printf ("The structures are unequal");

}

structcmp ( struct emp x, struct emp y)

{

     if (strcmp (x.n,y.n) ==0)

           if (x.age == y.age)

            return (0);

            return (1);

}

In short, if you nee to compare two structures, you'll have to write your own function to do so which carries out the comparison field by field.

Once a method declared as Final cannot be  overriden

Till the stack doesn't overflow