How to use Doubly Linked List with Dynamic Array? - c++

Question

My homework is about making a schedule with doubly-linked list. We can create a dynamic array for keeping days. But every day has to have a doubly-linked list which contains time slots. Vectors and arrays are forbidden from use, instead of linked lists. I have difficulty about functions.
This is my header file:
#ifndef _SCHEDULE_H
#define _SCHEDULE_H
#include <string>
using namespace std;
struct Node
{
string courseName;
int time;
Node *next; //forward direction
Node *prev; //backward direction
Node::Node() {}
Node::Node(const string &cName,const int&time, Node * pRight, Node * pLeft)
: courseName(cName),time(time),next(pRight), prev(pLeft)
{}
};
class Schedule
{
public:
Schedule(); //Constructor
//adding new course depend on time
void addCourse(string courseName, char day, int time,Node *Days[6]);
// delete course depend on time
void deleteCourse(char day, int time,Node *Days[6]);
// display a particular course's time
void displayCourse(string courseName,Node *Days);
//prints schedule
void print(Node *Days);
private:
Node *head; //Head node, start of a linked list based on Day
Node *tail; //Tail node, end of a linked list based on Day
};
#endif
Here's my implementation file:
#include <iostream>
#include "Schedule.h"
using namespace std;
Schedule::Schedule()
{
head=new Node(" ",0,NULL,NULL);
tail = NULL;
}
void Schedule::addCourse(string courseName, char day, int time,Node *Days[6])
{
int i;
if (day=='M')
{i=0;}
else if(day=='T')
{i=1;}
else if(day=='W')
{i=2;}
else if(day=='R')
{i=3;}
else if(day=='F')
{i=4;}
else if(day=='S')
{i=5;}
Node*cur=Days[i]->next=head;
if(Days[i]->next==NULL)
{
Days[i]=new Node;
Days[i]->next->courseName=courseName;
Days[i]->time=time;
Days[i]->next=NULL;
Days[i]->prev=NULL;
cout<<"The course "<<courseName<<" is added on "<<day<<" "<<time<<endl;
}
else if(time<Days[i]->next->time && time!=Days[i]->next->time)
{
Node*newcourse=new Node;
//Days[i]=new Node;
Days[i]->next->courseName=courseName;
Days[i]->next->time=time;
Days[i]->next=head;
Days[i]->prev=NULL;
Days[i]->next=newcourse;
cout<<"The course "<<courseName<<" is added on "<<day<<" "<<time<<endl;
}
else if(time>Days[i]->next->time)
{
while(Days[i]->next!=NULL && Days[i]->next->time<time && Days[i]->next->time!=time)
{
Days[i]->next=Days[i]->next->next;
}
if(Days[i]->next->time==time)
{
cout<<"Time conflict"<<endl;
}
else
{
Node*newcourse=new Node;
Days[i]->next->courseName=courseName;
Days[i]->next->time=time;
Days[i]->next=Days[i]->next->next;
Days[i]->prev=Days[i]->next;
Days[i]->next->next=newcourse;
cout<<"The course "<<courseName<<" is added on "<<day<<" "<<time<<endl;
}
}
}
void Schedule::deleteCourse(char day, int time,Node *Days[6])
{
int d;
if (day=='M')
{d=1;}
else if(day=='T')
{d=1;}
else if(day=='W')
{d=2;}
else if(day=='R')
{d=3;}
else if(day=='F')
{d=4;}
else if(day=='S')
{d=5;}
Node*cur=Days[d]->next=head;
if(Days[d]->next==NULL)
{
cout<<"Schedule is empty for this day"<<endl;
}
else
{
}
}
void Schedule::displayCourse(string courseName,Node *Days)
{
}
void Schedule::print(Node *Days)
{
}
Here is my main:
#include <iostream>
#include <fstream>
#include <string>
#include <sstream>
#include "Schedule.h"
using namespace std;
Node *Days = new Node[6];
void CoutSelection()
{
cout<<endl<<endl;
cout<<"Welcome to Schedule Maker. Please select an option:"<<endl;
cout<<" 1) Load the course schedule from a known file"<<endl;
cout<<" 2) Add a time slot manually"<<endl;
cout<<" 3) Remove a time slot manually"<<endl;
cout<<" 4) Print a particular course's time slot"<<endl;
cout<<" 5) Print all schedule"<<endl;
cout<<" 6) Exit" <<endl;
cout<<endl;
cout<<" Please enter your selection as 1-2-3-4-5-6"<<endl;
cout<<endl;
}
int main()
{
int selection;
CoutSelection();
cin>>selection;
Schedule list;
while (selection!=6)
{
if (selection==1)
{ string fileName;
cout<<"Please enter the filename that you want to load"<<endl;
cin>>fileName;
ifstream input;
input.open(fileName);//open file
if(!input.is_open())//control if correctly open
{
cout<<"Couldn't open input file: "<<fileName<<endl;
}
else
{
string cname,line; //course name and day identifier
char day;
int time; //time
while(!input.eof())
{getline(input, line);
stringstream ss(line);
int num;
ss>>cname>>day>>num;
list.addCourse(cname,day,time,*Days[6]);
}
}
}
else if (selection==2)
{
int timeAdded;
string cnameAdded;
char dayAdded;
cout<<"Please enter course name,day and it's time that you want to add like : coursename dayidentifier time"<<endl;
cout<<"Enter the day as M/T/W/R/F/S. (MONDAY:M, TUESDAY:T, WEDNESDAY:W, THURSDAY:R, FRIDAY:F, SATURDAY:S)"<<endl;
cin>>cnameAdded>>dayAdded>>timeAdded;
list.addCourse(cnameAdded,dayAdded,timeAdded,*Days[6]);
}
else if(selection==3)
{
char dayDeleted;
int timeDeleted;
cout<<"Please enter the day and time that you want to delete like : dayidentifider time"<<endl;
cout<<"Enter the day as M/T/W/R/F/S. (MONDAY:M, TUESDAY:T, WEDNESDAY:W, THURSDAY:R, FRIDAY:F, SATURDAY:S)"<<endl;
cin>>dayDeleted>>timeDeleted;
list.deleteCourse(dayDeleted,timeDeleted,*Days[6]);
}
else if(selection==4)
{
string coursedisplayed;
cout<<"Please enter course name that you want to display"<<endl;
cin>>coursedisplayed;
list.displayCourse(coursedisplayed,*Days);
}
else if(selection==5)
{
list.print(*Days);
}
CoutSelection();
cin>>selection;
}
return 0;
}
What is wrong with my code? If I handle one of the functions, I'm sure I can do other functions.
Errors :
error C2664: 'Schedule::addCourse' : cannot convert parameter 4 from 'Node' to 'Node *[]'
IntelliSense: no operator "*" matches these operands
operand types are: * Node

Answer 1

Aside from all the problems presented by #WhozCraig, which I think you should tackle for your own good. Your compiler is talking to you, and it is telling you that your addCourse method receives a pointer to a Node Array.
But in your main you called it with the following list.addCourse(cname,day,time,*Days[6]);. By doing *Days[6] you are telling the method you want to send what is pointed by Days[6]. Thus your compiler is receiving a Node object and not a pointer to a node array.
Try it with the following list.addCourse(cname,day,time,Days);, this will send the pointer to the first element in days.
One pointer to keep in mind, which you'll teacher will likely notice:
You have memory leaks, which is another VERY important subject.