C- Programs for LAB

Week 16
1

/* Write C programs that implement Queue (its operations) using i) Arrays */

#include
#include
#include
#define size 10
#define true 1
#define false 0

struct q_arr
{
int f,r;
int num;
int a[size];
};

void init(struct q_arr* queue);
int e_que(struct q_arr* queue);
int f_que(struct q_arr* queue);
int add_ele(struct q_arr* queue,int);
int rem_ele(struct q_arr* queue);
void display_ele(struct q_arr* queue);

/*main function*/
void main()
{
int ele,k;
int ch;

struct q_arr *queue = (struct q_arr*)malloc(sizeof(struct q_arr));
init(queue);

while(1)
{
clrscr();
printf(“\n\n****IMPLEMENTATION OF QUEUE USING ARRAYS****\n”);
printf(“============================================”);
printf(“\n\t\tMENU\n”);
printf(“============================================”);
printf(“\n\t[1] To insert an element”);
printf(“\n\t[2] To remove an element”);
printf(“\n\t[3] To display all the elements”);
printf(“\n\t[4] Exit”);
printf(“\n\n\t Enter your choice: “);
scanf(“%d”,&ch);

switch(ch)
{
case 1:
{
printf(“\nElement to be inserted:”);
scanf(“%d”,&ele);
add_ele(queue,ele);
break;
}

case 2:
{
if(!e_que(queue))
{
k=rem_ele(queue);
printf(“\n%d element is removed\n”,k);
getch();
}
else
{
printf(“\tQueue is Empty. No element can be removed.”);
getch();
}
break;
}

case 3:
{
display_ele(queue);
getch();
break;
}

case 4:
exit(0);

default:
printf(“\tInvalid Choice.”);
getch();
break;
}
}
}
/*end main*/

void init(struct q_arr* queue)
{
queue->f = 0;
queue->r = -1;
queue->num = 0;
}

/* Function to check is the queue is empty*/
int e_que(struct q_arr* queue)
{
if(queue->num==0)
return true;
return false;
}

/* Function to check if the queue is full*/
int f_que(struct q_arr* queue)
{
if(queue->num == size)
return true;
return false;
}

/* Function to add an element to the queue*/
int add_ele(struct q_arr* queue,int j)
{
if(f_que(queue))
return false;

if(queue->r == size – 1)
queue->r = -1;
queue->a[++queue->r] = j;
queue->num++;
return true;
}

/* Function to remove an element of the queue*/
int rem_ele(struct q_arr* queue)
{
int j;
if(e_que(queue))
return -9999;
j = queue->a[queue->f++];
if(queue->f == size)
queue->f = 0;
queue->num–;
return j;
}

/* Function to display the queue*/
void display_ele(struct q_arr* queue)
{
int j;
if(e_que(queue))
{
printf(“Queue is Empty. No records to display.”);
return;
}
printf(“\nElements present in the Queue are: “);
for(j=queue->f;j<=queue->r;j++)
printf(“%d\t”,queue->a[j]);
printf(“\n”);
}

2
/* Write C programs that implement Queue (its operations) using ii) Pointers */

#define true 1
#define false 0

#include
#include
#include

struct q_point
{
int ele;
struct q_point* n;
};

struct q_point *f_ptr = NULL;

int e_que(void);
void add_ele(int);
int rem_ele(void);
void show_ele();

/*main function*/
void main()
{
int ele,choice,j;
while(1)
{
clrscr();
printf(“\n\n****IMPLEMENTATION OF QUEUE USING POINTERS****\n”);
printf(“==============================================”);
printf(“\n\t\t MENU\n”);
printf(“==============================================”);
printf(“\n\t[1] To insert an element”);
printf(“\n\t[2] To remove an element”);
printf(“\n\t[3] To display all the elements”);
printf(“\n\t[4] Exit”);
printf(“\n\n\tEnter your choice:”);
scanf(“%d”, &choice);

switch(choice)
{
case 1:
{
printf(“\n\tElement to be inserted:”);
scanf(“%d”,&ele);
add_ele(ele);
getch();
break;
}

case 2:
{
if(!e_que())
{
j=rem_ele();
printf(“\n\t%d is removed from the queue”,j);
getch();
}
else
{
printf(“\n\tQueue is Empty.”);
getch();
}
break;
}

case 3:
show_ele();
getch();
break;

case 4:
exit(1);
break;

default:
printf(“\n\tInvalid choice.”);
getch();
break;
}

}
}

/* Function to check if the queue is empty*/
int e_que(void)
{
if(f_ptr==NULL)
return true;
return false;
}

/* Function to add an element to the queue*/
void add_ele(int ele)
{
struct q_point *queue = (struct q_point*)malloc(sizeof(struct q_point));
queue->ele = ele;
queue->n = NULL;
if(f_ptr==NULL)
f_ptr = queue;
else
{
struct q_point* ptr;
ptr = f_ptr;
for(ptr=f_ptr ;ptr->n!=NULL; ptr=ptr->n);
ptr->n = queue;
}
}

/* Function to remove an element from the queue*/
int rem_ele()
{
struct q_point* queue=NULL;
if(e_que()==false)
{
int j = f_ptr->ele;
queue=f_ptr;
f_ptr = f_ptr->n;
free (queue);
return j;
}
else
{
printf(“\n\tQueue is empty.”);
return -9999;
}
}

/* Function to display the queue*/
void show_ele()
{
struct q_point *ptr=NULL;
ptr=f_ptr;
if(e_que())
{
printf(“\n\tQUEUE is Empty.”);
return;
}
else
{
printf(“\n\tElements present in Queue are:\n\t”);
while(ptr!=NULL)
{
printf(“%d\t”,ptr->ele);
ptr=ptr->n;
}
}
}

This entry was posted on Sunday, December 13th, 2009 at 6:01 pm and is filed under Computer Science. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.