queuelinkedlist.c

#include<stdio.h>
#include<stdlib.h>
struct node{
    int data;
    struct node*next;
};

struct node*f= NULL;
struct node*r= NULL;
void traversal(struct node *ptr){
    while(ptr!=NULL){
        printf("elements %d\n", ptr->data);
        ptr = ptr->next;
    }
}
void enqueue(int val){
    struct node * n = (struct node*)malloc(sizeof(struct node));
    if (n == NULL){
        printf("overflow");
    }
    else{
        n->data = val;
        n->next = NULL;
        if(f== NULL){
            f=r=n;
        }
        else{
            r->next = n;
            r=n;
        }
    }
}
int dequeue(){
    int val = -1;
    struct node * n =f;
    if (f == NULL){
        printf("underflow");
    }
    else{
        f = f->next;
        val = n->data;
        free(n);
    }
    return val;
}

int main(){
    enqueue(45);
    enqueue(5);
    enqueue(4);
    traversal(f);
    printf("After dequeuing elements \n");
    printf("Element dequeued is %d \n", dequeue());
    traversal(f);
    return 0;
}