Я с трудом пытается сделать эти последние функции в моей программе односвязного списка:односвязано Список: Функции-члены
int size() const;
const std::string& get(int index) const throw (EmptyException, OutOfBoundException);
void remove(int index) throw (EmptyException, OutOfBoundException);
bool remove(const std::string& e);
bool removeAll(const std::string& e);
Я не знаю, как сделать это. Вот мой код
StringNode.h
#ifndef STRING_NODE_H
#define STRING_NODE_H
#include <string>
// A node in string singly linked list
class StringNode {
private:
// element value of a node
std::string elem;
// pointer to the next node in the list
StringNode *next;
// provide StringLinkedList access
friend class StringLinkedList;
};
#endif
StringLinkedList.h
#ifndef STRING_LINKED_LIST_H
#define STRING_LINKED_LIST_H
#pragma warning(disable: 4290)
#include "StringNode.h"
#include "Exception.h"
Строка односвязанны список класс StringLinkedList { частное: // указатель на голову списка StringNode * head; StringNode * Tail; // размер перечня int n;
public:
// default constructor
StringLinkedList();
// destructor
~StringLinkedList();
// ## this function is provided ##
// return the string representation of the list; each node is seperated
// by "->"
// example:
// "A->B->C" (without quotes)
// A is the head node, C is the tail
// "" (without quotes)
// empty list
std::string toString();
// return true if the list is empty, false otherwise
bool empty() const;
// return the number of nodes in the list
// note: take advantage of the private member we have, implement this
// running with O(1)
int size() const;
// return the element of front node
const std::string& front() const throw (EmptyException);
// return the element of back node
const std::string& back() const throw (EmptyException);
// return the element of a node at a specific index (index) of the list
// EmptyException is thrown if the list is empty
// The index should be in range of [0, n-1], which is 0 <= index <= (n-1)
// OutOfBoundException is thrown if index is out of that range
const std::string& get(int index) const throw (EmptyException, OutOfBoundException);
// add a new node with element e to the front of the list
void addFront(const std::string& e);
// add a new node with element e to the back of the list
void addBack(const std::string& e);
// insert a new node at a specific position (pos) of the list;
// the position should be in range of [0, n], which is 0 <= pos <= n.
// OutOfBoundException is thrown if index is out of that range
//
// example:
// A->B
// position can be inserted is 0 (before A), 1 (between
// A and B), 2 (after B); other positions will cause
// OutOfBoundException
void insert(int pos, const std::string& e) throw (OutOfBoundException);
// remove the front node from the list
// EmptyException is thrown if the list is empty
void removeFront() throw (EmptyException);
// remove the back node from the list
// EmptyException is thrown if the list is empty
void removeBack() throw (EmptyException);
// remove a node at a specific index (index) of the list; the
// index should be in range of [0, n-1], which is 0 <= index <= (n-1)
// OutOfBoundException is thrown if index is out of that range;
// EmptyException is thrown if the list is empty.
//
// example:
// A->B
// position can be removed is 0 (A), 1 (B); otherwise
// position will cause OutOfBoundException
void remove(int index) throw (EmptyException, OutOfBoundException);
// remove the first node that has a matched element e, starting from
// the head node; return true if a match is found, false otherwise
bool remove(const std::string& e);
// remove the ALL elements that are matched e; return true if a match
// is found, false otherwise
bool removeAll(const std::string& e);
// reverse the order of the list
// example:
// A->B->C->D
// after reverse(), D->C->B->A
void reverse();
};
#endif
StringLinkedList.cpp
#include "StringLinkedList.h"
// default constructor (COMPLETED)
StringLinkedList::StringLinkedList()
: head(NULL), n(0) { }
// destructor
StringLinkedList::~StringLinkedList()
{
while(!empty()) removeFront();
}
// return the string representation of the list; each node is seperated by "->"
std::string StringLinkedList::toString() {
// return blank if the list is empty
if (head == NULL)
return "";
// traverse to each node and append element of each
// node to final output string
std::string out = "";
StringNode *node = head;
while (node != NULL) {
out += node->elem + "->";
node = node->next;
}
// return final string without last "->"
return out.substr(0, out.size()-2);
}
bool StringLinkedList::empty() const
{return head==NULL;}
const std::string& StringLinkedList::front() const throw (EmptyException)
{
if(head==0)throw EmptyException("Empty head");
return head->elem;
}
const std::string& StringLinkedList::back() const throw (EmptyException)
{
if(tail==0)throw EmptyException("empty tail");
return tail->elem;
}
void StringLikedList::addFront(const std::string& e)
{
StringNode* v= new StringNode;
v->elem=e;
v->next=head;
head=v;
}
void StringLinkedList::addBack(const std::string& e)
{
StringNode* node=head;
while(node->next!=NULL)
node=node->next;
StringNode* v=new StringNode;
v->elem=e;
v->next=NULL;
node->next=v;
}
void StingLinkedList::removeFront() throw (EmptyException)
{
if(head==0) throw EmptyException("empty");
else
{
StringNode* remove;
remove=head;
if(head==tail)
{
head=NULL;
tail=NULL;
}
else
{
head=head->next;
}
delete remove;
}
}
void StringLinkedList::removeBack() throw (EmptyException)
{
if (tail==0)throw EmptyException("empty");
else
{
StringNode* remove;
remove=tail;
if(head==tail)
{
head=NULL;
tail=NULL;
}
else
{
StringNode* previousToTail=head;
while(previousToTail->next !=tail)
previousToTail=previousToTail->next;
tail=previousToTail;
tail->next=NULL;
}
delete remove;
}
}
void StringLinkedList::reverse()
{
StringNode* tempHead=head;
StringNode* nodes=NULL;
StringNode* nextNode=NULL:
if (head==NULL)
return;
tail=head;
nodes=head->next;
while(nodes!=NULL)
{
nextNode=nodes;
nodes=nodes->next;
nextNode->next=tempHead;
tempHead=nextNode;
}
head=tempHead;
tail->next=NULL;
}
спасибо за любую помощь
Вы говорите, что не знаете, как реализовать функцию 'size()'? – Nard