C Program to Reverse a Stack using Recursion
Posted by Superadmin on December 09 2015 04:16:00

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This C program, using recursion, reverses a stack content. Stack here is represented using a linked list. A linked list is an ordered set of data elements, each containing a link to its successor.

Here is the source code of the C program to display a linked list in reverse. The C program is successfully compiled and run on a Linux system. The program output is also shown below.

/*
* C Program to Reverse a Stack using Recursion
*/
#include <stdio.h>
#include <stdlib.h>

struct node
{
int a;
struct node *next;
};

void generate(struct node **);
void display(struct node *);
void stack_reverse(struct node **, struct node **);
void delete(struct node **);

int main()
{
struct node *head = NULL;

generate(&head);
printf("\nThe sequence of contents in stack\n");
display(head);
printf("\nInversing the contents of the stack\n");
if (head != NULL)
{
stack_reverse(&head, &(head->next));
}
printf("\nThe contents in stack after reversal\n");
display(head);
delete(&head);

return 0;
}

void stack_reverse(struct node **head, struct node **head_next)
{
struct node *temp;

if (*head_next != NULL)
{
temp = (*head_next)->next;
(*head_next)->next = (*head);
*head = *head_next;
*head_next = temp;
stack_reverse(head, head_next);
}
}

void display(struct node *head)
{
if (head != NULL)
{
printf("%d ", head->a);
display(head->next);
}
}

void generate(struct node **head)
{
int num, i;
struct node *temp;

printf("Enter length of list: ");
scanf("%d", &num);
for (i = num; i > 0; i--)
{
temp = (struct node *)malloc(sizeof(struct node));
temp->a = i;
if (*head == NULL)
{
*head = temp;
(*head)->next = NULL;
}
else
{
temp->next = *head;
*head = temp;
}
}
}

void delete(struct node **head)
{
struct node *temp;
while (*head != NULL)
{
temp = *head;
*head = (*head)->next;
free(temp);
}
}



$ cc pgm40.c
$ a.out
Enter length of list: 10

The sequence of contents in stack
1 2 3 4 5 6 7 8 9 10
Inversing the contents of the stack

The contents in stack after reversal
10 9 8 7 6 5 4 3 2 1