Интерфейс

4.2 Интерфейс

class Node {

public:

Node();

~Node();

friend class List;

private:

int Price;

int Number;

char Name[50];

Node *pNext;

};

class List {

public:

~List();

List();

Node* GetHead() const;

void Insert();

void Insert(char*, Node*);

void Remove(char*);

void Remove_(char*);

void Print(Node*) const;

void SetTail(Node*);

int Search(char*) const;

private:

Node *pHead;

Node *pTail;

};

int menu();

int Correct();

4.3 Реализация методов

#include <iostream>

#include <cassert>

#include <cstdlib>

using namespace std;

Node::Node() {

cout<<"Enter name: ";cin>>Name;

cout<<"Enter price (use only digits): ";Price = Correct();

cout<<"Enter number (use only digits): ";Number = Correct();

cout<<"Node constructor called; new entry created\n";

}

List::List() {

pHead = NULL;

pTail = NULL;

cout<<"List constructor called; new list created\n";

}

List::~List() {

Node* pTemp;

while (pHead) {

pTemp = pHead;

pHead = pHead->pNext;

delete pTemp;

cout<<"Destroying the list...\n";

}

}

Node* List::GetHead() const {

return pHead;

}

void List::Insert() {

if (pHead == NULL) {

pHead = new Node;

assert(pHead != NULL);

pHead->pNext = NULL;

pTail = pHead;

}

else {

pTail->pNext = new Node;

assert(pTail->pNext != NULL);

pTail = pTail->pNext;

pTail->pNext = NULL;

}

}

void List::Insert(char *Query, Node *Pointer) {

int Match;

Node *pNewNode;

if (Pointer == NULL) {

cout<<"No match found\n";

return;

} else {

Match = strcmp(Query, Pointer->Name);

if (Match == 0) {

pNewNode = new Node;

assert(pNewNode != NULL);

pNewNode->pNext = Pointer->pNext;

Pointer->pNext = pNewNode;

}else

Insert(Query, Pointer->pNext);

}

}

void List::Print(Node *Pointer) const {

if (Pointer == NULL)

return;

cout<<"Name: "<<Pointer->Name<<"";

cout<<"Price: "<<Pointer->Price<<"";

cout<<"Number: "<<Pointer->Number<<"\n";

Print(Pointer->pNext);

}

void List::Remove(char *Query) {

if (pHead == NULL) {

cout<<"The list is already empty\n";

return;

}

Node *pPrev = pHead;

Node *pTemp = pHead->pNext;

if (strcmp(Query, pHead->Name) == 0) {

pTemp = pHead;

pHead = pHead->pNext;

delete pTemp;

cout<<"Entry removed successfully\n";

return;

}

while (pTemp != NULL) {

if (strcmp(Query,pTemp->Name)==0)

break;

pPrev = pTemp;

pTemp = pTemp->pNext;

}

if (pTemp == NULL) {

cout<<"No match found";

return;

}

else {

pPrev->pNext = pTemp->pNext;

if (pTemp == pTail) {

delete pTemp;

SetTail(pHead);

cout<<"New tail of list assigned\n";

return;

}

delete pTemp;

cout<<"Entry removed successfully\n";

}

}

void List::Remove_(char *Query) {

int choice;

cout<<"(1) Remove only one entry with specified name\n";

cout<<"(2) Remove all entries with specified name: "; cin>>choice;

if (choice != 2) {

Remove(Query);

return;

}

while (Search(Query) == 1) {

Remove(Query);

}

}

int List::Search(char *Query) const {

Node *Pointer = pHead;

while (Pointer != NULL) {

if (strcmp(Query,Pointer->Name)==0)

return 1;

Pointer = Pointer->pNext;

}

return 0;

}

void List::SetTail(Node *Pointer) {

if (Pointer->pNext == NULL) {

pTail = Pointer;

return;

}

if (Pointer == NULL) {

pTail = pHead;

return;

}

SetTail(Pointer->pNext);

}

int menu() {

int choice;

cout<<"\n(1) Add entry";

cout<<"\n(2) Add entry after specified";

cout<<"\n(3) Remove entry";

cout<<"\n(4) Print the list";

cout<<"\n(5) Quit\n";

cout<<" Select action: ";

choice = Correct();

return choice;

}

int Correct() {

int number = 0; char buffer[10];

cin>>buffer;

for (int i = 0; i != 9; i++) {

if (buffer[i]>='0' && buffer[i]<='9')

number = number*10 + buffer[i] - '0';

}

return number;

}

Заключение

В данном курсовом проекте был реализован абстрактный тип данных – односвязный список на основе указателей.

В процессе реализации были соблюдены принципы объектно-ориентированного программирования. Особое внимание было уделено инкапсуляции данных и разработке интерфейса, исключающего нелигитимное модифицирование данных, определенных в задании.