Hey guys/gals for some reason in my main function my first while loop will not take in more than two values. any reasons why that wont happen? and just to be on the safe side, did I implement my remove function properly?
#ifndef SORTEDLIST_H
#define SORTEDLIST_H
#include<iostream>
using namespace std;
struct node
{
int info;
node* next;
node* previous;
};
class SortedList
{
public:
SortedList();
~SortedList();
void insert(int x);
void displayForward();
void displayReverse();
void remove(int x);
int getLength();
private:
node* getNode(int x);
bool exists(int x);
void insertAtBeg(node *p);
void insertAtEnd(node *p);
void insertInBetween(node *p);
node* listBeg; //pointer to the beginning of the list
node* listEnd; //pointer to the end of the list
int length; //size of the list
};
#endif#include "SortedList.h"
SortedList::SortedList()
{
length = 0;
listBeg = NULL;
listEnd = NULL;
}//constructor
SortedList::~SortedList()
{
while (listBeg != NULL)
{
node* next = listBeg->next;
delete listBeg;
listBeg = next;
}
}//destructor
void SortedList::insert(int x)
{
if(!exists(x))
{
node* p = getNode(x);
if(listBeg == NULL)
{
listBeg = p;
listEnd = p;
}else if (p->info < listBeg->info)
{
insertAtBeg(p);
}else if(p->info > listEnd->info)
{
insertAtEnd(p);
}else
{
insertInBetween(p);
}
length++;
}else
{
cout << "Error. Node already exists in the list. " << endl;
}
}//insert
void SortedList::displayForward()
{
node* t = listBeg;
while(t != NULL)
{
cout << t->info << " ";
t = t->next;
}
cout << endl;
}//displayForward
void SortedList::displayReverse()
{
node* t = listEnd;
while(t != NULL)
{
cout << t->info << " ";
t = t->previous;
}
cout << endl;
}//displayReverse
void SortedList::remove(int x)
{
if(exists(x))
{
node *p = new node;
p->info = x;
p->previous->next = p->next;
p->next->previous = p->previous;
delete p;
}else
{
cout << "Node selected cannot be deleted because it does not exist." << endl;
}
}//remove
int SortedList::getLength()
{
return length;
}//getLength
node* SortedList::getNode(int x)
{
node *p = new node;
p->info = x;
p->next = NULL;
p->previous = NULL;
return p;
}//getNode
bool SortedList::exists(int x)
{
node* t = listBeg;
bool found = false;
while(t != NULL)
{
if(t->info == x)
{
found = true;
t = t->next;
}
}
}//exists
void SortedList::insertAtBeg(node *p)
{
p->next = listBeg;
listBeg->previous = p;
listBeg = p;
}//insertAtBeg
void SortedList::insertAtEnd(node *p)
{
p->previous = listEnd;
listEnd->next = p;
listEnd = p;
}//insertAtEnd
void SortedList::insertInBetween(node *p)
{
node* t = listBeg;
while(t->info < p->info)
{
t = t->next;
}
p->next = t;
p->previous = t->previous;
t->previous->next = p;
t->previous = p;
}//insertInBetween//main program
#include "SortedList.h"
int main()
{
SortedList list;
int choice = 0;
while(choice != -1)
{
cout << "Choose a node to enter(-1 to stop):";
cin >> choice;
list.insert(choice);
}
cout << "Displaying List forward." << endl;
list.displayForward();
cout << "Displaying List in reverse." << endl;
list.displayReverse();
int del = 0;
while(del != -1)
{
cout << "Choose a node to delete(-1 to stop):";
cin >> del;
list.remove(del);
}
cout << "After deletion: " << endl;
cout << "Displaying List forward." << endl;
list.displayForward();
cout << "Displaying List in reverse." << endl;
list.displayReverse();
return 0;
}