malloc.txt

#include <stdio.h>
#include <stdlib.h>

struct node
{
    char data;
    struct node *next;
};

struct node *top = NULL;

void display();
void push(char);
void pop();
void destroy();

void main()
{
    int n;
    char ch;
    while (1)
    {
        printf("\n\nStack Menu\n1. Push \n2. Pop\n3. Display\n4. Destroy\n0. Exit\n");
        scanf("%d", &n);
        switch (n)
        {
        case 1:
            printf("\n\nEnter a character for pushing : ");
            scanf("%s", &ch);
            push(ch);
            break;
        case 2:
            pop();
            break;
        case 3:
            display();
            break;
        case 4:
            destroy();
            break;
        case 0:
            destroy();
            exit(0);
        default:
            printf("\nwrong choice.\n");
        }
    }
}

void push(char item)
{
    struct node *nptr = malloc(sizeof(struct node));
    nptr->data = item;
    nptr->next = top;
    top = nptr;
    printf("\n%c is pushed into the stack", item);
}

void display()
{
    printf("\nRemaining stack is : \n");
    struct node *temp;
    temp = top;
    while (temp != NULL)
    {
        printf("\n%c", temp->data);
        temp = temp->next;
    }
}

void pop()
{
    if (top == NULL)
    {
        printf("\nStack is empty\n");
    }
    else
    {
        struct node *temp = top;
        top = top->next;
        printf("\n%c", temp->data);
        free(temp);
    }
}

void destroy()
{
    if (top == NULL)
    {
        printf("\nStack is already empty\n");
    }
    else
    {
        struct node *temp = top;
        printf("\nRemaining stack is : \n");
        while (top != NULL)
        {
            pop();
        }
        printf("\nStack Dectroyed.");
    }
}