stacknqueuell

/* stack and queue using array difference */

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

/* linked list node struct */
struct node {
    int data;
    struct node *next;
};

/* for stack we use push and pop operation and for Queue we use enqueue/dequeue
   Stack is LIFO: Last In First Out 
   Queue is FIFO: First In First Out
/*

// stack

Push(int x)
{
   stuct node *temp = (strcut node *) malloc(sizeof(struct node));
   if (head == NULL)
   {
       head = temp;
       temp->data = x;
       temp->next = NULL;
       return;
   }  
   temp->data = x;
   temp->next = head;
   head = temp;
}

Pop()
{
   struct node *temp = head;
   head = temp->next;
   free(temp);
}   

//queue

struct node * rear = NULL;
struct node * front = NULL;

Enqueue(int x)
{
    struct node *temp = (struct node*)malloc (sizeof(struct node));
    temp->data = x;
    temp->next = NULL;
    if (font == NULL) && (rear == NULL)
    {
        front = rear = temp;
        return;
    }
    rear->next = temp;
    
}

Dequeue(int x)
{
    if (front == NULL) return;
    struct node *temp = front;
    if (front == rear)
    {
        front = rear = NULL;
    }    
    else
    {
        front = front->next;
    }
    free(temp);
}