Write the following C program using pointer: a) To sort the list of numbers through pointer. b) To reverse the string through pointer.

Dr. A.P.J. Abdul Kalam Technical University, Lucknow

KCS151 / KCS251 Programming for Problem Solving - Using C Language

Lab Exercises

41. Write the following C program using pointer
      a. To sort the list of numbers through pointer.
      b. To reverse the string through pointer.

a. To sort the list of numbers through pointer.

/*

 File: Prgrm41a.c

 Author: Aditya Saini

 Date: Jan 20, 2021

 Description: Program to sort the list of numbers through pointer.

*/

#include <stdio.h>

int main (void)

{

     int ar[20];

     int no_of_elements;

     int key;

     int i, j;

     //Input no of elements

     printf ("Input number of elements: ");

     scanf ("%d", &no_of_elements);

     //Input array

     printf ("Input elements: ");

     for (i = 0; i <= no_of_elements - 1; i++)

          scanf ("%d", &ar[i]);

     //Print Array

     printf ("Array: ");

     for (i = 0; i <= no_of_elements - 1; i++)

          printf ("%d ", ar[i]);

     //Sorting

     for (i = 1; i <= no_of_elements - 1; i++)

     {

          key = *(ar + i);

          for (j = i - 1; j >= 0 && *(ar + j) > key; j--)

               *(ar + j + 1) = *(ar + j);

          *(ar + j + 1) = key;

     }

     //Print Array after sorting

     printf ("\nSorted Array: ");

     for (i = 0; i <= no_of_elements - 1; i++)

          printf ("%d ", ar[i]);

     return 0;

};

Output

Input number of elements: 5

Input elements: 6 9 5 7 2

Array: 6 9 5 7 2

Sorted Array: 2 5 6 7 9

b. To reverse the string through pointer.

/*

 File: Prgrm41b.c

 Author: Aditya Saini

 Date: Jan 20, 2021

 Description: Program to reverse the string through pointer.

*/

#include <stdio.h>

int main (void)

{

     char str[20];

     int length;

     char temp;

     int i, j;

     //Input string

     printf ("Input string: ");

     fflush (stdin);

     gets(str);

     //Calculate string length

     length = 0;

     while (*(str + length) != '\0')

          length++;

     //Reverse string

     for (i = 0; i <= length / 2 - 1; i++)

     {

          temp = *(str + i);

          *(str + i) = *(str + length - 1 - i);

          *(str + length - 1 - i) = temp;

     }

     //Print reverse string

     printf ("Reverse String: ");

     puts (str);

     return 0;

};

Output

Input String: www.digitalg1.com

Reverse String: moc.1glatigid.www