Page 167 - DCAP407_DATA_STRUCTURE

Data Structure

main ()
{
/* A character array S whose size is 80 is declared */
char S[80];

printf ("\n Enter a string: \n");
/* gets function declared in stdio.h header file reads a line from standard
input and stores it in S. */
gets (S);
printf("\nThe reversed string: \n");

/* print_reverse function is called with the argument S */
print_reverse (S);
/* Waits until a key is pressed */
getch();
}
Output:
Enter the string to be reversed: english
Output String : hsilgne

In this example:
1. First, the stdio.h header file is included using the include keyword.
2. Then, a recursive function named print_reverse is declared. The function
takes a parameter S, which is a character pointer.
3. In the print_reverse () method:

(a) First, using an ‘if’ condition, the value of string pointer S is checked. If
the value is not equal to NULL, a recursive call is made by passing the
incremented value of S.

(b) Finally, the value of S is decremented and the string pointer value is
written using putchar().
4. Then, the main () function is executed.
5. Then, a character array S whose size is 80, is declared.
6. Then, gets function is used to read a line from the standard input and this is
stored in S.
7. Then, print_reverse function is invoked with the argument S.
8. Finally, getch() prompts the user to press any key and when the key is
pressed, the program is terminated.

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