Program to reverse a linked list using stack

linked_list_reverse.c

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

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

void enqueue(struct node**,struct node **,int);
void dequeue(struct node**,struct node **);
void traverse(struct node*,struct node*);
void push(struct node**,struct node**);
struct node* pop(struct node**);
void listrev(struct node**,struct node**);
void free_queue(struct node*);
void free_stack(struct node*);
int isstackempty(struct node*);

int main()
{
	int key;
	struct node *front=NULL,*rear=NULL;
	FILE *fp;
	fp=fopen("input","r");
	fscanf(fp,"%d",&key);
	while(!feof(fp))
	{
		enqueue(&front,&rear,key);
		fscanf(fp,"%d",&key);
	}
	traverse(front,rear);
	listrev(&front,&rear);
	traverse(front,rear);
	free_queue(front);
	return 0;
}

void enqueue(struct node** front,struct node** rear,int num)
{
	struct node* newnode=malloc(sizeof(struct node));
	newnode->val=num;
	newnode->next=NULL;
	if(*front==NULL)
		*front=*rear=newnode;
	else
	{
		(*rear)->next=newnode;
		(*rear)=newnode;
	}
}

void dequeue(struct node** front,struct node** rear)
{
	struct node* temp=NULL;
	if(*front==*rear)
	{
		temp=*front;
		*front=*rear=NULL;
	}
	else if(*front!=NULL)
	{
		temp=*front;
		*front=(*front)->next;
	}
	if(temp!=NULL)
	{
		temp->next=NULL;
		free(temp);
	}
}

void free_queue(struct node* front)
{
	while(front!=NULL)
	{
		free(front);
		front=front->next;
	}
}

void traverse(struct node* front,struct node* rear)
{
	struct node* temp=front;
	while(temp!=NULL)
	{
		printf("%d",temp->val);
		if(temp!=rear)
			printf("--->");
		else
			printf("\n");
		temp=temp->next;
	}
}

void push(struct node** top,struct node** newnode)
{
	(*newnode)->next=NULL;
	if(*top==NULL)
		*top=*newnode;
	else
	{
		(*newnode)->next=*top;
		*top=*newnode;
	}
}

struct node* pop(struct node** top)
{
	struct node* temp=NULL;
	if(!isstackempty(*top))
	{
		temp=(*top);		
		*top=(*top)->next;
	}
	temp->next=NULL;
	return temp;
}

int isstackempty(struct node* top)
{
		if(top==NULL)
			return 1;
		else
			return 0;
}

void listrev(struct node** front,struct node** rear)
{
	struct node *temp1=NULL,*temp2=NULL,*top=NULL;
	temp1=*front;
	while(temp1!=NULL)
	{
		temp2=temp1->next;
		push(&top,&temp1);
		temp1=temp2;
	}
	if(!isstackempty(top))
		*front=pop(&top);
	temp1=*front;
	while(!isstackempty(top))
	{
		temp2=pop(&top);
		temp1->next=temp2;
		temp1=temp2;
	}
	*rear=temp1;
}

/*
Linked list is read from a file called input

Content of the file is integers

*/

itna bda!!!!