Implementation of Queue using Linked list in C.

Here is the code..

//OPERATION ON SIMPLE QUEUE USING LINK LIST

#include<stdio.h>

#include<stdlib.h>

typedef struct q

{

int info;

struct q *next;

} node;

node *start=NULL;

void insert();

int del();

void traverse();

void main()

{

int ch;

char choice;

clrscr();

printf("----1. insertion\n");

printf("----2. deletion\n");

printf("----3. traverse\n");

printf("----4. exit\n");

do

{

printf("Enter your choice\t");

scanf("%d",&ch);

switch(ch)

{

case 1: insert();

break;

case 2: printf("the deleted element is %d\n",del());

break;

case 3: traverse();

break;

case 4: 

exit(2);

default: printf("wrong choice\n");

}

}

while(1);

}

void insert()

{

node *p,*temp;

temp=start;

p=(node *)malloc(sizeof(node *));

printf("Enter the data\t\t");

scanf("%d",&p->info);

p->next=NULL;

if(start==NULL)

{

start=p;

}

else

{

while(temp->next!=NULL)

{

temp=temp->next;

}

temp->next=p;

}

}

int del()

{

node *temp;

int value;

if(start==NULL)

{

printf("queue is empty\n");

return(0);

}

else

{

temp=start;

value=temp->info;

start=start->next;

free(temp);

}

return(value);

}

void traverse()

{

node *temp;

temp=start;

while(temp->next!=NULL)

{

printf("%d\t",temp->info);

temp=temp->next;

}

printf("%d\n",temp->info);

}

For Turbo C users.

//OPERATION ON SIMPLE QUEUE USING LINK LIST

#include<stdio.h>

#include<conio.h>

#include<alloc.h>

#include<stdlib.h>

typedef struct q

{

int info;

struct q *next;

} node;

node *start=NULL;

void insert();

int del();

void traverse();

void main()

{

int ch;

char choice;

clrscr();

printf("----1. insertion\n");

printf("----2. deletion\n");

printf("----3. traverse\n");

printf("----4. exit\n");

do

{

printf("Enter your choice\t");

scanf("%d",&ch);

switch(ch)

{

case 1: insert();

break;

case 2: printf("the deleted element is %d\n",del());

break;

case 3: traverse();

break;

case 4: getch();

exit(2);

default: printf("wrong choice\n");

}

}

while(1);

}

void insert()

{

node *p,*temp;

temp=start;

p=(node *)malloc(sizeof(node *));

printf("Enter the data\t\t");

scanf("%d",&p->info);

p->next=NULL;

if(start==NULL)

{

start=p;

}

else

{

while(temp->next!=NULL)

{

temp=temp->next;

}

temp->next=p;

}

}

int del()

{

node *temp;

int value;

if(start==NULL)

{

printf("queue is empty\n");

return(0);

}

else

{

temp=start;

value=temp->info;

start=start->next;

free(temp);

}

return(value);

}

void traverse()

{

node *temp;

temp=start;

while(temp->next!=NULL)

{

printf("%d\t",temp->info);

temp=temp->next;

}

printf("%d\n",temp->info);

}