# Thread: Recursion Revisited again, and again!

1. Should I post the ENTIRE code? That way you can look at everything?

2. Doesn't hurt.

3. OK I will.
This is the class definition:
Code:
```#ifndef H_OrderedListType
#define H_OrderedListType

#include <iostream>
#include "arrayListType.h"

using namespace std;

template<class elemType>
class orderedArrayListType: public arrayListType<elemType>
{
public:
void insertOrd(const elemType&);

int binarySearch(const elemType& item);

int seqSearch(const elemType& item);

orderedArrayListType(int size = 100);
private:
int binarySearchImpl(const elemType& item, int first, int last);
};

template<class elemType>
void orderedArrayListType<elemType>::insertOrd(const elemType& item)
{
int first = 0;
int last = length - 1;
int mid;

bool found = false;

if(length == 0)   //list is empty
{
list[0] = item;
length++;
}
else
if(length == maxSize)
cerr<<"Cannot insert into a full list."<<endl;
else
{
while(first <= last && !found)
{
mid = (first + last) / 2;

if(list[mid] == item)
found = true;
else
if(list[mid] > item)
last = mid - 1;
else
first = mid + 1;
}//end while

if(found)
cerr<<"The insert item is already in the list. "
<<"Duplicates are not allowed.";
else
{
if(list[mid] < item)
mid++;

insertAt(mid, item);
}
}
}//end insertOrd

template<class elemType>
int orderedArrayListType<elemType>::binarySearch(const elemType& item)
{
int first = 0;
int last = length - 1;
return binarySearchImpl(item, first, last);
}

//Function written for Test 5 Question 22
template<class elemType>
int orderedArrayListType<elemType>::binarySearchImpl(const elemType& item, int first, int last)
{

if(first >= last)
return -1;
int mid = (first + last) / 2;
if(list[mid] == item)
return mid;
if (list[mid] > item)
return binarySearchImpl(item, first, mid - 1);
else
return binarySearchImpl(item, mid + 1, last);
}//end binarySearch

template<class elemType>
int orderedArrayListType<elemType>::seqSearch(const elemType& item)
{
for (int loc = 0; loc < length; loc++)
if (list[loc] == item)
return loc;
return -1;
}//end seqSearch on ordered list

template<class elemType>
orderedArrayListType<elemType>::orderedArrayListType(int size)
: arrayListType<elemType>(size)
{
}

#endif```
This is the driver. Most of this code was source code from the text website. I only had to deal with changing the iterative binary search to a recursive function.
And then test it.
Code:
```#include <iostream>

#include "orderedArrayListType.h"

using namespace std;

int main()
{
orderedArrayListType<int> intList(10);			 			//Line 1

int counter;											//Line 3
int number;

cout<<"Line 5: Processing the integer list"
<<endl;												//Line 5
cout<<"Line 6: Enter 5 integers (small to large): ";	//Line 6

for(counter = 0; counter < 5; counter++)				//Line 7
{
cin>>number;						 				//Line 8
intList.insertAt(counter, number);		 			//Line 9
}

cout<<endl;												//Line 10
cout<<"Line 11: The list you entered is: ";				//Line 11
intList.print();										//Line 12
cout<<endl;												//Line 13

//using binarySearch function
cout << "Enter a number to find in the list: ";
int x;
cin >> x;
int pos1 = intList.binarySearch(x);
if( pos1 == -1)
{
cout << "The number " << x << " was not found in: ";
intList.print();
cout<<endl;
}
else
{
cout << "The number " << x << " was found in: ";
intList.print();
cout << "at position number: " << pos1 + 1 << endl;
}

cout<<"Line 14: Enter the item to be deleted: ";		//Line 14
cin>>number;											//Line 15
intList.remove(number);									//Line 16
cout<<"Line 17: After removing "<< number
<<", the list is: ";								//Line 17
intList.print();										//Line 18
cout<<endl;												//Line 19

int intListSize;										//Line 36

cout<<"Line 37: Enter the size of the integer "
<<"list: ";						 				//Line 37
cin>>intListSize;										//Line 38

orderedArrayListType<int> intList2(intListSize);		//Line 39

cout<<"Line 40: Processing the integer list"
<<endl;											//Line 40
cout<<"Line 41: Enter "<<intListSize
<<" integers (small to large): ";					//Line 41

for(counter = 0; counter < intListSize; counter++) 		//Line 42
{
cin>>number;										//Line 43
intList2.insertAt(counter, number);		 		//Line 44
}

cout<<endl;												//Line 45
cout<<"Line 46: The list you entered is: ";				//Line 46
intList2.print();										//Line 47

//using binarySearch function
cout << "Enter a number to find in the list: ";
int y;
cin >> y;
int pos2 = intList2.binarySearch(y);
if( pos2 == -1)
{
cout << "The number " << y << " was not found in: ";
intList2.print();
cout<<endl;
}
else
{
cout << "The number " << y << " was found in: ";
intList2.print();
cout << "at position number: " << pos2 + 1 << endl;
}
cout << endl;												//Line 48
return 0;
}```
I really appreciate your help in this. I am going crazy!

4. Just a note, but the base class is missing from your code.

5. Do you want me to post the parent? I can do that, but I thought this was way long as it is.

6. Base Class:
Code:
```#ifndef H_arrayListType
#define H_arrayListType

#include <iostream>
#include <cassert>

using namespace std;

template <class elemType>
class arrayListType
{
public:
const arrayListType<elemType>& operator=(const arrayListType<elemType>&);

bool isEmpty();
//Function to determine whether the list is empty
//Postcondition: Returns true if the list is empty;
//        	    otherwise, returns false.
bool isFull();
//Function to determine whether the list is full
//Postcondition: Returns true if the list is full;
//               otherwise, returns false.
int listSize();
//Function to determine the number of elements in the list
//Postcondition: Returns the value of length.
int maxListSize();
//Function to determine the size of the list
//Postcondition: Returns the value of maxSize.
void print() const;
//Function to output the elements of the list
//Postcondition: Elements of the list are output on the
//               standard output device.
bool isItemAtEqual(int location, const elemType& item);
//Function to determine whether the item is the same
//as the item in the list at the position specified by location
//Postcondition: Returns true if the list[location]
//               is the same as the item; otherwise,
//		     returns false.
void insertAt(int location, const elemType& insertItem);
//Function to insert an item in the list at the
//position specified by location. The item to be inserted
//is passed as a parameter to the function.
//Postcondition: Starting at location, the elements
//               of the list are shifted down,
//               list[location] = insertItem;, and
//               length++;
//       If the list is full or location is out of
//	   range, an appropriate message is displayed.
void insertEnd(const elemType& insertItem);
//Function to insert an item at the end of the list
//The parameter insertItem specifies the item to be
//inserted.
//Postcondition: list[length] = insertItem; and length++;
//               If the list is full, an appropriate
//               message is displayed.
void removeAt(int location);
//Function to remove the item from the list at the
//position specified by location
//Postcondition: The list element at list[location] is
//               removed and length is decremented by 1.
//       If location is out of range, an appropriate message
//       is displayed.
void retrieveAt(int location, elemType& retItem);
//Function to retrieve the element from the list at the
//position specified by location
//Postcondition: retItem = list[location]
//      If location is out of range, an appropriate
//      message is displayed.
void replaceAt(int location, const elemType& repItem);
//Function to replace the elements in the list at the
//position specified by location. The item to be replaced
//is specified by the parameter repItem.
//Postcondition: list[location] = repItem
//      If location is out of range, an appropriate
//      message is displayed.
void clearList();
//Function to remove all the elements from the list
//After this operation, the size of the list is zero.
//Postcondition: length = 0;
int seqSearch(const elemType& item);
//Function to search the list for a given item.
//Postcondition: If the item is found, returns the location
//               in the array where the item is found;
//               otherwise, returns -1.
void insert(const elemType& insertItem);
//Function to insert the item specified by the parameter
//insertItem at the end of the list. However, first the
//list is searched to see whether the item to be inserted
//Postcondition: list[length] = insertItem and length++
//     If the item is already in the list or the list
//     is full, an appropriate message is displayed.
void remove(const elemType& removeItem);
//Function to remove an item from the list. The parameter
//removeItem specifies the item to be removed.
//Postcondition: If removeItem is found in the list,
//      it is removed from the list and length is
//      decremented by one.

arrayListType(int size = 100);
//constructor
//Creates an array of the size specified by the
//parameter size. The default array size is 100.
//Postcondition: The list points to the array, length = 0,
//               and maxSize = size

arrayListType(const arrayListType<elemType>& otherList);
//copy constructor

~arrayListType();
//destructor
//Deallocates the memory occupied by the array.

protected:
elemType *list; 	//array to hold the list elements
int length;		    //variable to store the length of the list
int maxSize;		//variable to store the maximum size of the list
};

template <class elemType>
bool arrayListType<elemType>::isEmpty()
{
return (length == 0);
}

template <class elemType>
bool arrayListType<elemType>::isFull()
{
return (length == maxSize);
}

template <class elemType>
int arrayListType<elemType>::listSize()
{
return length;
}

template <class elemType>
int arrayListType<elemType>::maxListSize()
{
return maxSize;
}

template <class elemType>
void arrayListType<elemType>::print() const
{
for(int i = 0; i < length; i++)
cout<<list[i]<<" ";
cout<<endl;
}

template <class elemType>
bool arrayListType<elemType>::isItemAtEqual
(int location, const elemType& item)
{
return(list[location] == item);
}

template <class elemType>
void arrayListType<elemType>::insertAt
(int location, const elemType& insertItem)
{
if(location < 0 || location >= maxSize)
cerr<<"The position of the item to be inserted "
<<"is out of range"<<endl;
else
if(length >= maxSize)  //list is full
cerr<<"Cannot insert in a full list"<<endl;
else
{
for(int i = length; i > location; i--)
list[i] = list[i - 1];	//move the elements down

list[location] = insertItem;	//insert the item at the
//specified position

length++;	//increment the length
}
} //end insertAt

template <class elemType>
void arrayListType<elemType>::insertEnd(const elemType& insertItem)
{
if(length >= maxSize)  //the list is full
cerr<<"Cannot insert in a full list"<<endl;
else
{
list[length] = insertItem;	//insert the item at the end
length++;	//increment length
}
} //end insertEnd

template <class elemType>
void arrayListType<elemType>::removeAt(int location)
{
if(location < 0 || location >= length)
cerr<<"The location of the item to be removed "
<<"is out of range"<<endl;
else
{
for(int i = location; i < length - 1; i++)
list[i] = list[i+1];

length--;
}
} //end removeAt

template <class elemType>
void arrayListType<elemType>::retrieveAt
(int location, elemType& retItem)
{
if(location < 0 || location >= length)
cerr<<"The location of the item to be retrieved is "
<<"out of range"<<endl;
else
retItem = list[location];
} // retrieveAt

template <class elemType>
void arrayListType<elemType>::replaceAt
(int location, const elemType& repItem)
{
if(location < 0 || location >= length)
cerr<<"The location of the item to be replaced is "
<<"out of range"<<endl;
else
list[location] = repItem;

} //end replaceAt

template <class elemType>
void arrayListType<elemType>::clearList()
{
length = 0;
} // end clearList

template <class elemType>
int arrayListType<elemType>::seqSearch(const elemType& item)
{
int loc;
bool found = false;

for(loc = 0; loc < length; loc++)
if(list[loc] == item)
{
found = true;
break;
}

if(found)
return loc;
else
return -1;
} //end seqSearch

template <class elemType>
void arrayListType<elemType>::insert(const elemType& insertItem)
{
int loc;

if(length == 0)					 //list is empty
list[length++] = insertItem; //insert the item and
//increment the length
else
if(length == maxSize)
cout<<"Cannot insert in a full list."<<endl;
else
{
loc = seqSearch(insertItem);

if(loc == -1)   //the item to be inserted
//does not exist in the list
list[length++] = insertItem;
else
cerr<<"the item to be inserted is already in "
<<"the list. No duplicates are allowed."<<endl;
}
} //end insert

template <class elemType>
void arrayListType<elemType>::remove(const elemType& removeItem)
{
int loc;

if(length == 0)
cerr<<"Cannot delete from an empty list."<<endl;
else
{
loc = seqSearch(removeItem);

if(loc != -1)
removeAt(loc);
else
cout<<"The item to be deleted is not in the list."
<<endl;
}

} //end remove

template <class elemType>
arrayListType<elemType>::arrayListType(int size)
{
if(size < 0)
{
cerr<<"The array size must be positive. Creating "
<<"an array of size 100. "<<endl;

maxSize = 100;
}
else
maxSize = size;

length = 0;

list = new elemType[maxSize];
assert(list != NULL);
}

template <class elemType>
arrayListType<elemType>::~arrayListType()
{
delete [] list;
}

//copy constructor
template <class elemType>
arrayListType<elemType>::arrayListType
(const arrayListType<elemType>& otherList)
{
maxSize = otherList.maxSize;
length = otherList.length;
list = new elemType[maxSize]; 	//create the array
assert(list != NULL);	//terminate if unable to allocate
//memory space

for(int j = 0; j < length; j++)  //copy otherList
list [j] = otherList.list[j];
}//end copy constructor

template <class elemType>
const arrayListType<elemType>& arrayListType<elemType>::operator=
(const arrayListType<elemType>& otherList)
{
if(this != &otherList)	//avoid self-assignment
{
delete [] list;
maxSize = otherList.maxSize;
length = otherList.length;

list = new elemType[maxSize];
assert(list != NULL);

for(int i = 0; i < length; i++)
list[i] = otherList.list[i];
}

return *this;
}

#endif```

7. Well, I'm trying to get an understand of how it works, but calls to the base class are present and I can't see them. You can attach the source file (or header) in case it's too long.

I also notice that you create a list of a size of 10:
Code:
`orderedArrayListType<int> intList(10);`
But you ask and insert 5 numbers.

8. Yea, Everything other than the two calls in the driver and the rewrite of the binarySearch is all from the textbook source code.

9. I also notice that this class is kind of dangerous. I suggest you ONLY create a list big enough to hold all your numbers (ie, size = 5), and not more. It also seems more reasonable to use insert instead of insertAt, since you're just putting them in order.
If you don't set the size correctly, there's a small change you can get false answers (because of junk in the array).

10. I assumes that everything that was written was correct since it was from the author. Should set the default to 5 since that is what he wrote in the program to enter?
But, then the bottom call (there are two parts - one the list size is set the second the list size is set by the user).

11. Where does the error occour? The first or second part?

12. In the driver, I change this:

orderedArrayListType<int> intList(5);

13. It looks fine to me (but there's probably some subtle bug somewhere that I'm just missing). I don't have a debugger here, but I'd love to debug this >_<
Someone else may help, I can't do it right now.

14. In the top part, if I enter 5 integers:
2 3 4 5 6
and ask to find 2 or 6 they aren't.
but the delete works no matter which number.

On the bottom part it doesn't find any number, no matter how big or small I define the list. And no matter which number I ask to find.

15. Well, I think I have to leave it alone, it is almost 4am and I need to get up at 5 to get ready for work. I may stay up and keep playing with the code to see if I can come up with something. But, I will leave the board and hope a miracle happens tomorrow morning.
I won't be able to visit the board while at work, but I will check it when I get home tomorrow evening.

Thanks for your time and help Elysia, and Mats, and iMalc.
I haven't put this one to bed yet, but I would love to.