CS 11001 Programming and Data Structure

Assignment 9 : Structure and Linked Lists Date : 26^th March, 07

Tutorial Outlines:

Structure
Array of Structures through Pointers
Self Referential Structure: Linked Lists

Illustrative Example of a C program of how to declare a structure, initialization and

accessing its element:

Solution:

#include <stdio.h>

void main()
{
typedef struct     //Definition of a structure
{
int no;
char acc_name[15];
float balance;
} account;

account a1,a2; // Structure Declaration
account a3={467,"sameer",2456}; // Structure can be initialized like that

printf("\n Enter account number, names and balance :\n");
scanf("%d%s%f",&a1.no,a1.acc_name,&a1.balance);
printf("\n Enter account number, names and balance :\n");
scanf("%d%s%f",&a2.no,a2.acc_name,&a2.balance);

printf("A/C No.=%d\tName = %s\tBalance = %f\n",a1.no,a1.acc_name,a1.balance);
printf("A/C No.=%d\tName = %s\tBalance = %f\n",a2.no,a2.acc_name,a2.balance);
printf("A/C No.=%d\tName = %s\tBalance = %f\n",a3.no,a3.acc_name,a3.balance);
}

Assign. 9A:

Write a C program for addition of two complex numbers using structure.

Test Run:

Input Output

2+3i, 5+2i 7+5i

4+7i, 7+8i 11+15i

Tutorial 9B (Array of structure as pointer):

Illustrative example of how to pass array of structures as pointers to a function.

Write a C function to display an array of structure.

Solution:

#include <stdio.h>
#include <malloc.h>

typedef struct //Definition of a structure
{
int no;
float balance;
} account;

void disp(account *acc_ptr, int n);
void main()
{
int i,n;
account *acc_ptr;//Pointer to the structure used as array

printf("Enter the number of records :");
scanf("%d",&n);

acc_ptr=malloc(n*sizeof(account));// Dynamic memory allocation

for (i=0;i<n;i++)
{
printf("\nEnter the %d number Record (A/C No. and Balance):\n",i);
scanf("%d%f",&acc_ptr[i].no,&acc_ptr[i].balance);//Storing the array of //structure
}
disp(acc_ptr,n);//Passing the pointer to structure to a function
}

void disp(account *acc_ptr, int n)
{
int i;

printf("\nThe records are: \n\n");
for (i=0;i<n;i++)
printf("%d\t%f\n\n",(acc_ptr+i)->no,(acc_ptr+i)->balance); //Accessing

//data from array of structure
}

Assignment 4B:

Write a C function to sort the array of structure with respect to

a) marks

b) d.o.b.

c) name (in lexical order)

d) roll no.

Hint: You can use the following structure

struct student

{

int Roll_no;

struct dob

{

int day;

int month;

int year;

};

char name[20];

int marks;

};

Tutorial 9C (Self Referential Structure: Lined Lists):

Write a C program for implementing a linked list with functions as append, display and count.

append : It appends a value as the last element of the list.

display : It shows the elements of the linked list.

count: It counts the number of elements presents in the linked list.

Solution:

#include <stdio.h>
#include <malloc.h>

struct node        //Definition of a self referential structure
{
int d;
struct node *link; //Note that link is pointer to the same structure (self reference)
};

void append(struct node **q, int n);
void display(struct node *q);
int count(struct node *q);

void main()
{
struct node *ptr;      //ptr is a pointer to the structure
int n,i,data;
ptr=NULL;              //empty linked list

printf("\nEnter the number of elements you want to append to the list :\n");
scanf("%d",&n);

for (i=0;i<n;i++) //Reading
{
printf("\nEnter the elements to be appended :\n");
scanf("%d",&data);
append(&ptr,data);
}

display(ptr);
printf("\n\nNo. of elements in the Linked List = %d\n\n",count(ptr));
}

void append(struct node **q, int n)

// Note that q is pointer to the pointer to the structure

{
struct node *t;

t=*q;

if (*q==NULL) //Create the first node when the list is empty
{
*q=malloc(sizeof(struct node));
t=*q;
}
else
{
while (t->link!=NULL) //go to last node
t=t->link;
t->link=malloc(sizeof(struct node)); //dynamic memory allocation of a node
t=t->link;
}
t->d=n;
t->link=NULL;
}

void display(struct node *q)
{
printf("\n\nThe elements of the Linked List :\n\n");

while (q!=NULL) //traverse the entire linked list
{
printf("%d\t",q->d);
q=q->link;
}
}

int count(struct node *q)
{
int count=0;

while (q!=NULL) //traverse the entire linked list
{
count++;
q=q->link;
}
return count;
}