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CSE 2341Object Oriented Programming

with C++

Note Set #18

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Overview

• Dynamic Data structures with linked lists

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Linked List

• Series of connected nodes• Can grow/shrink at runtime

– dynamic allocation of nodes allows for this

Data

Null

Head

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Linked List Node

Data

struct ListNode{

double data;ListNode* next;

};

ListNode is a self referential data structure.

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Basic Linked List Operations

• Basic Operations of LL– appending a node– traversing the list– inserting a node– deleting a node– destroying the list

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Class NumberListclass NumberList{private: struct ListNode { double value; ListNode* next; }; ListNode* head;

private: NumberList() {head = NULL;} ~NumberList(); void appendNode(double); void insertNode(double); void deleteNode(double); void displayList();};

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AppendNodevoid NumberList::appendNode(double num){ ListNode* newNode, *nodePtr; newNode = new ListNode; newNode -> value = num; newNode -> next = NULL;

if(!head) //If there aren’t any nodes in listhead = newNode;

else {

nodePtr = head;while(nodePtr->next)

nodePtr = nodePtr->next;nodePtr -> next = newNode;

}}

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Append

5

3 4 Null

Null

Head

newNode

NodePtr

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Append

5

3 4 Null

Null

Head

newNode

NodePtr

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Append

5

3 4

Null

Head

newNode

NodePtr

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Display List

void NumberList::DisplayList(){ ListNode* nodePtr; nodePtr = head; while(nodePtr) {

cout << nodePtr->value << endl;nodePtr = nodePtr->next;

}}

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Display

53 4 Null

Head

NodePtr

3

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Display

53 4 Null

Head

NodePtr

34

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Display

53 4 Null

Head

NodePtr

345

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Display

53 4 Null

Head

NodePtr

345

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Insert A Nodevoid NumberList::insertNode(double num){ ListNode *newNode, *nodePtr, *previousNode; newNode = new ListNode; newNode -> value = num;

if(!head) { head = newNode;

newNode->next = NULL; } else { nodePtr = head;

previousNode = NULL;

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Insert A Node//Continued from previous slidewhile(nodePtr != NULL && nodePtr->value < num){ previousNode = nodePtr; nodePtr = nodePtr->next;}if(previousNode == NULL) //if insert as first{ head = newNode; newNode -> next = nodePtr;}else{ previousNode -> next = newNode; newNode -> next = nodePtr;}

}}

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Insert

53 4 NullHead

NodePtr

4.5

newNode

PreviousNode

Null

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Insert

53 4 NullHead

NodePtr

4.5

newNode

PreviousNode

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Insert

53 4 NullHead

NodePtr

4.5

newNode

PreviousNode

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Insert

53 4 NullHead

NodePtr

4.5

newNode

PreviousNode

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Insert

53 4 NullHead

NodePtr

4.5

newNode

PreviousNode

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Insert

53 4 NullHead

NodePtr

4.5

newNode

PreviousNode

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Insert

53 4 NullHead

NodePtr

4.5

newNode

PreviousNode

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Deleting A Nodevoid NumberList::deleteNode(double num){ ListNode *nodePtr, *previousNode; if(!head)

return; if(head->value == num) {

nodePtr = head->next;delete head;head = nodePtr;

} else { nodePtr = head;

while(nodePtr != NULL && nodePtr->value != num) { previousNode = nodePtr; nodePtr = nodePtr->next;}if(nodePtr) { previousNode->next = nodePtr -> next; delete nodePtr;

} }}

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Delete

53 4 NullHead

NodePtr

PreviousNode

Null

num4

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Delete

53 4 NullHead

NodePtr

num4

PreviousNode

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Delete

53 4 NullHead

NodePtr

num4

PreviousNode

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Delete

53 4 NullHead

NodePtr

num4

PreviousNode

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Fini

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