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Pointers and 2-Dimensional arrays in C programming

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            Multi-dimensional array can also be represented with an equivalent pointer notation as in single dimensional array. A two dimensional array is actually a collection of one dimensional arrays. Therefore we can define a two dimensional array as a pointer to a group of contiguous one-dimensional arrays. Its general syntax is as
  Data_type (*ptr_variable)[expression2];
            Instead of
         Data_type array[expression1][expression2];
   

   Example:
   Suppose x is a two dimensional integer array having 4 rows and 5 columns. We can declare x as
int (*x)[5];
   rather than
int x[4][5];
                    Here, in first declaration, x is defined to be a pointer to a group of contiguous one dimensional 5-element integer arrays. The x points to the first 5-element array, which is actually first row of the two dimensional array. Similarly, x+1 points to the second 5-element array, which is the second row of the two dimensional array. It is illustrated as

An example:

 void main()
     {
  int p[2][3]={   {1,2,3},
                           {4,5,6}
                          };
   clrscr();
   printf("p=%u\tp+1=%u",p,p+1);
   printf("\n*p=%u\t*(p+1)=%u",*p,*(p+1));
   printf("\n*(p+0)+1=%u\t*(p+1)+1=%u",*(p+0)+1,*(p+1)+1);
   printf("\n*(*(p+0)+1)=%u\t*(*(p+1)+1)=%u",*(*(p+0)+1),*(*(p+1)+1));
   getch();
    }

Output:
p=65514                 p+1=65520
*p=65514               *(p+1)=65520
*(p+0)+1=65516    *(p+1)+1=65522
*(*(p+0)+1)=2        *(*(p+1)+1)=5

    It can be illustrated as



Example:
         Write a program to add two 2*3 matrixes using pointer.

void main()
 {
     int (*a)[3],(*b)[3],*(sum)[3],i,j;
     clrscr();
     printf("Enter first matrix:\n");
     for(i=0;i<2;i++)
            for(j=0;j<3;j++)
               scanf("%d",*(a+i)+j);

      printf("Enter second Matrix:\n");
     for(i=0;i<2;i++)
            for(j=0;j<3;j++)
               scanf("%d",*(b+i)+j);

    printf("\nThe sum matrix is:\n");
     for(i=0;i<2;i++)
       {
            for(j=0;j<3;j++)
              {
*(x+2)+1)
 
               *(*(sum+i)+j)= *(*(a+i)+j)+ *(*(b+i)+j);
               printf("\t%d",*(*(sum+i)+j));

              }
       printf("\n");
      }
     getch();

 }  
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