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CT077-3-2-DSTR Data Structures 2

Objectives

By the end of this esson! you "i#

• Be a$e to i%&e%ent the $asic o&erations on

inked ists – Searchin' for aues in the ist

– ccessin' (set and 'et aues in the ist)

–

Deetin' ite%s fro% the ist – *nsertin' ite% at ar$itrary &osition in the ist

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Searching for an Item in the List

• Deter%ine e+istence (Booean resut) of an ite%in a inked ist! "here the data structure is#

– ,hen infos ty&e is an o$.ect! search &ara%eter can$e a key fied of that ty&e! such as *D fied

class NodeType {public:

int info;NodeType* link;

};

class LinkedList { public:

NodeType* head;

int size;

bool search(int value); !! the other i"ple"ented "ethods};

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CT077-3-2-DSTR Data Structures /

Searching for an Item in the List

•Traerse a ist ee%ents and co%&ared "ithdesired aue

class LinkedList { !!data "e"bers and other "ethods bool search(int value){

NodeType * current # head; $hile(current %# N&LL) if (current'info ## value)

return true; else

current # current'link;

return false;}};

list!search()

current

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CT077-3-2-DSTR Data Structures

Accessing List Elements

•

1et ee%ents info at a 'ien inde+class LinkedList { !!data "e"bers and other "ethods int +et,te"-t(int inde.){ if(inde./0 11 inde.#size){

cout // 2,nde. out of bound!3n2 ;abort(); } NodeType * current # head; for(int i#0; i/inde.; i44)

current # current'link; return current'info;

}};

ote that accessin' an

ee%ent at a 'ien

rando% &osition is so"

co%&ared "ith arrays

The $i''er the inde+! the

so"er the o&eration

list!+et,te"-t(5)

current

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Accessing List Elements

• Set ee%ents info at a 'ien inde+

class LinkedList { !!data "e"bers and other "ethods void set,te"-t(int value6 int inde.){ if(inde./0 11 inde.#size){

cout // 2,nde. out of bound!3n2 ;abort();

} NodeType * current # head; for(int i#0; i/inde.; i44)

current # current'link;

current'info # value;}};

ote that accessin' an

ee%ent at a 'ienrando% &osition is so"

co%&ared "ith arrays

The $i''er the inde+! the

so"er the o&eration

list!set,te"-t(76)

current

9

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Deleting List Items

• Deete the first ee%ent in a inked istclass LinkedList { !!data "e"bers and other "ethods void delete8irst(){ if(size 0){else6 "ay $ant to +ive a "essa+e or

errorNodeType * to9eeleted # head;head # head'link;delete to9eeleted;size'';

}}

};

to9eeleted

X

3X

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Deleting Last Item in the List

class LinkedList {

!!data "e"bers and other "ethods void deleteLast(){ if(size 0){else6 "ay $ant to +ive a "essa+e orerror

if (size ## ){list has only one ite"delete head;

head # N&LL;}else{ NodeType * beforeLast # head; $hile (beforeLast'link'link %# N&LL) beforeLast # beforeLast'link; delete beforeLast'link;

beforeLast'link # N&LL;}size'';

}}

};

beforeLast

X

3X

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Deleting an Item at Arbitrary Index

class LinkedList {

!!data "e"bers and other "ethods void delete,te"-t(int inde.){ if(inde. / size){else6 "ay $ant to +ive a "essa+e orerror

if (inde. ## 0) delete8irst();else{

NodeType * prev # N&LL6 * toelete # head; for (int i#0; i/inde.; i44){ prev # toelete; toelete # toelete'link; } prev'link # toelete'link; N&LL also

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Insert ne Item at Arbitrary Index

class LinkedList {

!!data "e"bers and other "ethods void insert,te"-t(int value6 int inde.){ if(inde. /# size){else6 "ay $ant to +ive a "essa+e orerror

if (inde. ## 0) insert-t9e+innin+(value);else if (inde. ## size)

insert-t>nd(value);else { NodeType * ne$Node # ne$ NodeType; ne$Node'info #

value; NodeType * prev # head;

for (int i#0; i/inde.'; i44)

prev # prev'link; ne$Node'link # prev'link; prev'link # ne$Node; size44;}

}}

};ist!insert,te"-t(?65) ne$Node

X

prev!

"

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Exercises

•Check your i%&e%entation for a &reious functionaities usin'the foo"in' &ro'ra%#

,hat is the e+&ected out&ut of the &ro'ra% at each check&oint8

void "ain(){LinkedList list;

istinserttBe'innin'()9istinsertt:nd(2)9

istinserttBe'innin'(3)9

ist&rint()9

istdeete;irst()9

ist&rint()9

istdeeteLast()9

ist&rint()9istcear()9

@heckpoint

istinserttBe'innin'()9

istinsertt:nd(7)9

istinsertt:nd(5)9

istinserttBe'innin'(/)9istdeete*te%t(3)9

ist&rint()9

@heckpoint 5istinsert*te%t(4! 2)9

istinsert*te%t(3! 0)9

ist&rint()9

istinsert*te%t(6! ist'etSi

8/16/2019 07 DS Linked Lists 2 (1)


07 ds linked lists 2 (1)

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