zFzzzy - Online C Compiler & Debugging Tool

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

typedef struct node{
    int val;
    struct node*next;
}Node;

Node*head=NULL;

Node*createN(int x){
    Node*newnode;
    newnode=(Node*)malloc(sizeof(Node));
    newnode->val=x;
    newnode->next=NULL;
    return newnode;
}

void freeL(){
    Node*p;
    while(head!=NULL){
        p=head->next;
        free(head);
        head=p;
    }
}

void printL(){
    Node*p=head;
    while(p!=NULL){
        printf("%d ",p->val);
        p=p->next;
    }
    printf("\n");
}

void push(int x){
    Node*newnode=createN(x);
    newnode->next=head;
    head=newnode;
}

int pop(){
    if(head==NULL)return 0;
    int val=head->val;
    Node*temp=head;
    head=head->next;
    free(temp);
    return val;
}

void enqueue(int x){
    Node*newnode=createN(x);
    if(head==NULL){
        head=newnode;
    }else{
        Node*p=head;
        while(p->next!=NULL)p=p->next;
        p->next=newnode;
    }
}

int dequeue(){
    if(head==NULL)return 0;
    int val=head->val;
    Node*temp=head;
    head=head->next;
    free(temp);
    return val;
}

int main(void){
    int s1,s2,s3,q1,q2,q3;

    push(1);
    push(2);
    push(3);
    s1=pop();
    s2=pop();
    s3=pop();
    printf("%d %d %d\n",s1,s2,s3);

    enqueue(1);
    enqueue(2);
    enqueue(3);
    q1=dequeue();
    q2=dequeue();
    q3=dequeue();
    printf("%d %d %d\n",q1,q2,q3);

    freeL();
    return 0;
}