UNIT I LINEAR DATA STRUCTURES – LIST .pptx

KONGUNADU COLLEGE OF ENGINEERING AND
TECHNOLOGY
DEPARTMENT OF INFORMATION TECHNOLOGY
20CS301 - DATA STRUCTURES
Subject Handled by
Mrs. R.Aruna,AP / IT
KNCET.

UNIT - I LINKEDLIST
Abstract Data types (ADTs) — List ADT — Array-
based implementation — Linked list
implementation — Singly linked lists — Circularly
linked lists — Doubly linked lists — Applications
of lists — Polynomial Manipulation.

UNIT - II STACKS AND QUEUES
Stack ADT — Operations — Applications —
Evaluating arithmetic expressions — Conversion of
Infix to postfix expression — Queue ADT —
Operations — Implementation — Applications of
Queues.

UNIT-III TREES
Tree ADT — Tree Traversals — Binary Tree ADT —
Expression Trees — Applications of Trees — Binary
Search Tree ADT — AVL Trees — Splay Tree — B
—Tree — Heap — Applications of heap.

UNIT IV GRAPHS
Definitions — Topological Sort — Shortest-Path
Algorithms — Dijkstra's Algorithm Minimum
Spanning Tree — Prim's algorithms — Depth-First
Traversal — Biconnectivity Euler circuits —
Applications of graphs.

UNIT V SORTING AND HASHING TECHNIQUES
Sorting — Merge sort — Quick sort — Insertion sort —
Shell sort — Radix sort; Hashing — Hash Functions —
Collision resolution techniques — Linear Probing —
Separate Chaining — Open Addressing — Rehashing —
Extendible Hashing.

INTRODUCTION TO DATA STRUCTURES AND
LIST ADT

DEFINITION:
• Data Structure is a way of organizing, storing and retrieving
data and their relationships with each other

CLASSIFICATION OF DATA STRUCTURES

ADT –ABSTRACT DATA TYPE
• It is a type for objects whose behavior is defined by set of values and set
of operations from user point of view
• Mentions only what operations are to be performed but not how they will
be implemented
• Thus, ADT is the specification of a data type within some language,
independent of implementation

ADT –ABSTRACT DATA TYPE
• Examples - List ADT, Stack ADT, Queue ADT, etc., Some
operations on these ADT are:
List:
•insert(x)
•delete(x)
•find(x)
Stack:
•Push (x)
•Pop()
•isFull()
•isEmpty()
Queue:
•enqueue()
•dequeue()
•isFull()
•isEmpty()

LIST ADT
• List ADT can be represented in two ways
– Array
– Linked List

ARRAY ADT
• Collection of elements of same data type
• Elements in an array is stored in adjacent memory location
• Syntax:
datatype arrayname [size]
Eg : int a [50];
Operations:
• insertion()
• deletion()
• search()

ISSUES IN ARRAY
• Fixed size: Resizing is expensive
• Requires continuous memory for allocation
– Difficult when array size is larger
• Insertions and deletions are inefficient
– Elements are usually shifted
• Wastage of memory space unless the array is full

ARRAY IMPLEMENTATION OF LIST ADT
Output:
Main Menu
1.Create 2.Delete 3.Search 4.Insert 5.Display 6.Exit
Enter your Choice 1
Enter the number of nodes 3
Enter the Element 8 9 7
Main Menu
Enter your Choice 2
Enter the position u want to delete 2
The Elements after deletion 8 7
Main Menu
Enter your Choice 4
Enter the position u need to insert 2
Enter the element to insert 6
The list after insertion 8 6 7
Main Menu
Enter your Choice 6

CREATE
void create()
{
printf(“n Enter the number of nodes”);
scanf(“%d”, &n);
for(i=0;i<n;i++)
{
printf(“n Enter the Element:”,i+1);
scanf(“%d”, &b[i]);
}
}

DELETE
void deletion()
{
printf(“n Enter the position u want to delete::”);
scanf(“%d”, &pos);
if(pos>=n)
{
printf(“n Invalid Location::”);
}
else
{
for(i=pos+1;i<n;i++)
{
b[i-1]=b[i];
}
n—;
}
printf(“n The Elements after deletion”);
for(i=0;i<n;i++)
{
printf(“t%d”, b[i]);
}
}

SEARCH
void search()
{
printf(“n Enter the Element to be searched:”);
scanf(“%d”, &e);
for(i=0;i<n;i++)
{
if(b[i]==e)
{

printf(“Value is in the %d Position”, i);
}
else
{
printf(“Value %d is not in the list::”, e);
continue;
}

INSERT
void insert()
{
printf(“n Enter the position u need to insert::”);
scanf(“%d”, &pos);
if(pos>=n)
{
printf(“n invalid Location::”);
}
else
{

for(i=MAX-1;i>=pos-1;i—)
{
b[i+1]=b[i];
}
printf(“n Enter the element to insert::n”);
scanf(“%d”,&p);
b[pos]=p;
n++;
}
printf(“n The list after insertion::n”);
display();
}

DISPLAY
void display()
{
printf(“n The Elements of The list ADT are:”);
for(i=0;i<n;i++)
{
printf(“nn%d”, b[i]);
}

LINKED LIST ADT
• Linked list is a linear data structure
• Made up of chain of nodes
• Each node contains a data and a pointer to the next node in the
chain
• Last node of the list is pointed to NULL

REPRESENTATION OF NODE IN LINKED LIST
• Each node contains two fields:
– Data field: Contains data element to be stored
– Pointer field: Contains the address of next node
Declaration of a node:
struct node
{
int data;
struct node *next;
};

CREATING A NODE
Statement to create a node:
n= (struct node*) malloc(sizeof(struct node))
nnext=NULL;
Struct node
{
Int data;
Struct node *next;
} *n;

TYPES OF LINKED LIST
• Singly linked list
• Doubly linked list
• Circular linked list

SINGLY LINKED LIST (SLL)
• Each node contains only one pointer field that contains the
address of the next node in the list

OPERATIONS ON SINGLY LINKED LIST
Major operations are:
•Insertion
–At the beginning
–At the middle
–At the end
•Deletion
–At the beginning
–At the middle
–At the end
•Search
Global declaration of a Node:
struct node
{
int data;
struct node *next;
} *head, *tail, *n, *t;

ROUTINE FOR INSERTION AT THE BEGINNING
void ins_beg(int num) //Let num=10
{
n=(struct node *) malloc(size of(struct node));
nnext=NULL;
ndata=num;
if (head==NULL) //case 1
{
head=n;
tail=n;
}
else //case 2
{
nnext=head;
head=n;
}
}

ROUTINE FOR INSERTION AT THE END
void ins_end(int num) //Let num=10
{
nnext=NULL;
ndata=num;
{
head=n;
tail=n;
}
else //case 2
{
tailnext=n;
tail=n;
}
}

ROUTINE FOR INSERTION AT THE MIDDLE
void ins_end(int num, int mid_data) //Let num=10, mid_data=9
{
nnext=NULL;
ndata=num;
for(t=head; t!=NULL; t=tnext)
{
if(tdata==mid_data)
break;
}
nnext=tnext;
tnext=n;
}
10
300
83==9? NO 9==9? YES
10
300
1500
300

ROUTINE FOR DELETION AT THE BEGINNING
void del_beg()
{
t=head;
head=tnext;
free(t);
}

ROUTINE FOR DELETION AT THE END
void del_end()
{
Struct node *tp;
t=head;
while(tnext!=NULL)
{
tp=t;
t=tnext;
}
tail=tp;
tailnext=NULL;
free(t);
}
1000 850 1500 2500

ROUTINE FOR DELETION AT THE MIDDLE
void del_mid(int num) //Let num=70
{
Struct node *tp;
t=head;
while(tdata!=num)
{
tp=t;
t=tnext;
}
tpnext=tnext;
free(t);
}
83!=70? Yes 9!=70? Yes
2800
70!=70? NO
1500

ROUTINE FOR SEARCH AN ELEMENT
Struct node* search (int num) //Let num=9
{
t=head;
while(t!=NULL && tdata!=num)
{
t=tnext;
}
return t;
}

LINKED LIST –ADVANTAGES & DISADVANTAGES
Advantages:
•No wastage of memory
–Memory allocated and deallocated as per requirement
•Efficient insertion and deletion operations
Disadvantages:
•Occupies more space than array to store a data
–Due to the need of a pointer to the next node
•Does not support random or direct access

DOUBLY LINKED LIST (DLL)
•Type of linked list
•Each node contains two pointer fields that contains the address of
the next node and that of previous node in the list

REPRESENTATION OF NODE IN DLL
•Each node contains three fields:
–Data: Contains data element to be stored
–next: Contains the address of next node
–prev: Contains address of previous node
Declaration of a node:
structnode
{
intdata;
structnode *next, *prev;
};

OPERATIONS ON DOUBLY LINKED LIST
Major operations are:
•Insertion
–At the beginning
–At the middle
–At the end
•Deletion
–At the beginning
–At the middle
–At the end
•Search
Global declaration of a Node:
structnode
{
intdata;
structnode *next, prev;
} *head, *tail, *n, *t;

void ins_beg_dll(intnum) //Let num=70
{
nnext=NULL;
nprev=NULL;
ndata=num;
if(head==NULL) //case 1
{
head=n;
tail=n;
}
else //case 2
{
nnext=head;
headprev=n;
head=n;
}
}
70
1000
500
500

void ins_end_dll(int num) //Let num=10
{
n=(structnode *) malloc(size of(struct node));
nnext=NULL;
nprev=NULL;
ndata=num;
{
head=n;
tail=n;
}
else //case 2
{
tailnext=n;
nprev=tail;
tail=n;
}
}
500
500
2500

void ins_end_dll(intnum, intmid_data) //Let num=10, mid_data=9
{
n=(structnode *) malloc(size of(structnode));
nnext=NULL;
nprev=NULL;
ndata=num;
for(t=head; t!=NULL; t=tnext)
{
break;
}
nnext=tnext;
nprev=t;
tnextprev=n;
tnext=n;
}
500
500
2500

void del_beg_dll()
{
t=head;
head=headnext;
headprev=NULL;
free(t);
}
t is freed

void del_end_dll()
{
t=head;
while(tnext!=NULL)
{
t=tnext;
}
tail=tailprev;//tail=tprev;
tailnext=NULL;
free(t);
}
t is freed

void del_mid_dll(int num) //Let num=9
{
t=head;
{
t=tnext;
}
tprevnext=tnext;
tnextprev=tprev;
free(t);
}
9 != 9 NO
1500 1000
free t

ROUTINE FOR SEARCH AN ELEMENT
structnode* search_dll(intnum) //Let num=9
{
t=head;
while(t!=NULL && tdata!=num)
{
t=tnext;
}
return t;
}
9 != 9 NO

DLL –ADVANTAGES & DISADVANTAGES
Advantages:
•Can traverse in both directions
•Operations in the middle of the list can be done efficiently
–No need of extra pointer (tp) to track the previous node
•Reversing the list is easy
Disadvantage:
•Space required to store a data is even more higher than SLL
–Due to the use of two pointers

CIRCULAR LINKED LIST (CLL)
•Type of linked list
•The last node will be pointing to the first node
•It can be either singly or doubly linked
Global declaration of a node:
Struct node
{
Int data;
Struct node *next, *prev;
}*head,*n,*t;
1000

void ins_beg_cll(int num) //Let num=10
{
nnext=NULL;
ndata=num;
{ head=n;
nnext=head;
}
else //case 2
{ t=head;
while(tnext!=head)
t=tnext;
tnext=n;
nnext=head;
head=n;
}
}
X
10
850 != 1000 YES 1500 != 1000 YES 2500 != 1000 YES 1000 != 1000 NO
1000
X
10
100
100
1000 100

void ins_end_cll(int num) //Let num=10
{
nnext=NULL;
ndata=num;
t=head;
t=tnext;
tnext=n;
nnext=head;
}
1000
X
10
100
X
10
100
100 1000

void ins_end_cll(int num, int mid_data) //Let num=10, mid_data=9
{
nnext=NULL;
ndata=num;
for(t=head; tnext!=head; t=tnext)
{
break;
}
nnext=tnext;
tnext=n;
}
10
300
83==9 NO 9==9? YES
10
300
1500
300
1000
300

1000
void del_beg_cll()
{
Struct node *t1;
t=head;
t1=head;
t=tnext;
tnext=headnext;
head=tnext;
free(t1);
}
850 != 1000 YES 1500 != 1000 YES 2500 != 1000 YES 1000 != 1000 NO
850

void del_end_cll()
{
Struct node *tp;
t=head;
{
tp=t;
t=tnext;
}
tpnext=head;
free(t);
}
1000
1000

void del_mid_cll(int num) //Let num=9
{
Struct node *tp;
t=head;
{
tp=t;
t=tnext;
}
tpnext=tnext;
free(t);
}
1000
1500

ROUTINE FOR SEARCH
Struct node* search_cll (int num) //Let num=9
{
t=head;
while(tnext!=head && tdata!=num)
{
t=tnext;
}
return t;
}

CLL –ADVANTAGES & DISADVANTAGES
Advantage:
•Comparing to SLL, moving to any node from a node is
possible
Disadvantages:
•Reversing a list is complex compared to linear linked list
•If proper care is not taken in managing the pointers, it
leads to infinite loop
•Moving to previous node is difficult, as it is needed to
complete an entire circle

APPLICATIONS OF LIST
Lists can be used to
•Sort elements
•Implement stack and queue
•Represent graph (adjacent list representation)
•Implement hash table
•Implement multiprocessing of applications
•Manipulate polynomial equations

POLYNOMIAL ADT
•A polynomial equation is an equation that has multiple
terms made up of numbers and variables. Polynomials
can have different exponents.
•Polynomial manipulations such as addition, subtraction
can be performed.

Examples of polynomial equations:
–9x5
+ 7x3
– 4x2
+ 8
7x4
– 17x3
– 8x2
To store the data of polynomial equations in the linked list, each
node contains two data fields, namely coefficient, power and one
next pointer field
struct node
{
int coeff;
int pow;
struct node *next;
}*n;

CREATING A POLYNOMIAL LIST
void create_poly(int c, int p, struct node *t)
{ struct node *head, *tail;
//head=t;
n=(struct node*) malloc(size of(struct node));
n->coeff=c;
n->pow=p;
n->next=null;
if (head==null)
{ head=n;
tail=n;
}
else
{ tail->next=n;
tail=n;
}
return head;
}

POLYNOMIAL ADDITION
Void add_poly(struct node *poly1, struct node *poly2, struct node *poly)
{
while(poly1!=NULL && poly2!=NULL)
{
if(poly1pow>poly2pow)
{
polypow=poly1pow;
polycoeff=poly1coeff;
ploy1=poly1next;
}
else if(poly1pow < poly2pow)
{
polypow=poly2pow;
poly2=poly2next;
}

POLYNOMIAL ADDITION CONTD.,
else
{ polypow=ploy1pow;
polycoeff=poly1coeff + poly2coeff;
ploy1=poly1next;
ploy2=poly2next;
}
}
while(poly1 != NULL || poly2 != NULL)
{ if (poly1 != NULL)
ploy1=poly1next;
}
if (poly2 != NULL)
ploy2=poly2next;
} } }

POLYNOMIAL SUBTRACTION
else
polycoeff=poly1coeff - poly2coeff;
ploy1=poly1next;
ploy2=poly2next;
}
}
while(poly1 != NULL || poly2 != NULL)
{ if (poly1 != NULL)
ploy1=poly1next;
}
if (poly2 != NULL)
ploy2=poly2next;
} } }

RADIX SORT:
• Radix sort is one of the sorting algorithms used to sort a
list of integer numbers in order. In radix sort algorithm,
a list of integer numbers will be sorted based on the
digits of individual numbers.
• Radix sort algorithm requires the number of passes
which are equal to the number of digits present in the
largest number among the list of numbers.
• For example, if the largest number is a 3 digit number
then that list is sorted with 3 passes.

UNIT I LINEAR DATA STRUCTURES – LIST .pptx

Multi-Linked Lists
•A multilinked list is a more general linked list with multiple
links from nodes.
•In a general multi-linked list each node can have any
number of pointers to other nodes,
•Multi-lists are essentially the technique of embedding
multiple lists into a single data structure.
•A multi-list has more than one next pointer, like a doubly
linked list, but the pointers create separate lists

UNIT I LINEAR DATA STRUCTURES – LIST .pptx

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