This is a homework assignment!
I am tasked with creating two doubly linked lists, one for even numbers and one for odd numbers. The lists will be populated by reading in from a file of integers. I must search the correct list (either even or odd, depending on the number from the file) to see if the number read from the file is already in the list. If it is, I have to ignore the number and move on. We are not allowed to use OOP, but are working on the concept of ADT's. Please do not include any OOP in your answer as I am not allowed to use it, and I have no clue how to read it yet.
When I run my code it compiles without errors, but it returns a -1. After doing some debugging, I find that it is reading in and inserting the first number for each list, but then getting hung up during the insertion of the second number. However, I can't seem to figure out what is causing it to exit with -1. If anyone could point me in the right direction as to where the problem is I would greatly appreciate it.
Oh, also, the program takes the file names of the file you want to read the integers from and another file that will be used later in the program (I have not gotten to that part yet) as command line arguments.
#include <iostream>
#include <fstream>
#include <cstddef>
#include <iomanip>
using namespace std;
struct doublyLinkList{
int numberRead;
doublyLinkList* prev;
doublyLinkList* next;
};
struct topAndCounter{
int counter;
doublyLinkList* head;
};
void initializeList(topAndCounter& aLinkList);
bool searchOrderedList(topAndCounter aLinkList, int tempIntHold);
void orderedListInsertion(topAndCounter& aLinkList, bool& success, int tempIntHold);
bool isEmptyList(topAndCounter& aLinkList);
int main(int argC, char* argV[]) // allows usage of command line arguments
{
ifstream intsForList;
ifstream intsToSearchFor;
topAndCounter evenList; // even list struct
topAndCounter oddList; // odd list struct
int tempIntHold; // holds integer read in from file
string storeIntsFile; // holds name of file
string intsToFindFile; // holds name of file
bool success = true; // whether memory was successfully allocated
cout << endl << endl;
cout << "Program to read in and store a list of unique integers from one ";
cout << "file and match numbers to it from a second file." << endl << endl;
switch(argC) // takes the argument count
{
case 1:
cout << "You didn't enter any filenames on the command line." << endl;
cout << "Please enter them now" << endl;
cout << "Filename for list of integers to store: ";
cin >> storeIntsFile;
cout << "Filename for integers to search list for: ";
cin >> intsToFindFile;
break;
case 2:
cout << "You didn't enter the file name of integers to search the list";
cout << " for" << endl;
cout << "Please enter it now: ";
cin >> intsToFindFile;
storeIntsFile = argV[1];
break;
case 3:
storeIntsFile = argV[1];
intsToFindFile = argV[2];
break;
}
intsForList.open(storeIntsFile.c_str()); // trys to open first file
intsToSearchFor.open(intsToFindFile.c_str()); // tries to open second file
// if files are not opened successful
if ((!intsForList) || (!intsToSearchFor))
{
while(!intsForList) // while the first file is not opened successfully
{
cout << "File for integers to populate list not found. " << endl;
cout << "Please enter another filename: ";
cin >> storeIntsFile;
intsForList.open(storeIntsFile); // try to open file
} // end while
while(!intsToSearchFor) // while the second file is not opened successfully
{
cout << "File containing integers to search list for not found.";
cout << endl;
cout << "Please enter another filename: ";
cin >> intsToFindFile;
intsToSearchFor.open(intsToFindFile); // try to open file
} // end while
} // end if
initializeList(evenList); // function call to initialize list to NULL
initializeList(oddList); // function call to initialize list to NULL
intsForList >> tempIntHold; // read in the first integer from the file
while((intsForList) && (success)) // while there is still integers in the file and memory
// allocated successfully
{
if (tempIntHold % 2 == 0) // if the number read from the file is even
{
orderedListInsertion(evenList, success, tempIntHold); // call the even sort funct
} // end if
else // if the number is odd
{
orderedListInsertion(oddList, success, tempIntHold); // odd num sort funct
} // end else
intsForList >> tempIntHold; // try to read next integer in file
} // end while
return 0;
}
void initializeList(topAndCounter& aLinkList)
{
aLinkList.counter = 0;
aLinkList.head = NULL; // initialize head pointer to null
return;
}
// function to search the list to see if the number read in from file is already in list
bool searchOrderedList(topAndCounter aLinkList, int tempIntHold)
{
bool found = false;
doublyLinkList* searchNode; // pointer for searching list
searchNode = aLinkList.head; // set pointer to top of list
while ((searchNode != NULL) && (!found)) // there are nodes in list and the number is
// not found
{
if (searchNode -> numberRead >= tempIntHold)
{
found = true;
}
else
{
searchNode = searchNode -> next; // move pointer to next node
}
}
if (found)
{
found = (searchNode -> numberRead == tempIntHold);
}
return found;
} // end function
void orderedListInsertion(topAndCounter& aLinkList, bool& success, int tempIntHold)
{
doublyLinkList* newNode;
doublyLinkList* searchNode;
bool intInUse;
bool found;
newNode = new (nothrow) doublyLinkList;
if (newNode != NULL)
{
intInUse = searchOrderedList(aLinkList, tempIntHold);
if (intInUse)
{
cout << "The current interger is already in the list. It will now ";
cout << "be ignored" << endl;
} // end if
else
{
newNode -> numberRead = tempIntHold;
if (isEmptyList(aLinkList))
{
newNode -> prev = NULL;
newNode -> next = NULL;
aLinkList.head = newNode;
} // end if
else
{
searchNode = aLinkList.head;
found = false;
while((searchNode != NULL) && (!found))
{
if (searchNode -> numberRead > newNode -> numberRead)
{
found = true;
} // end if
else
{
searchNode = searchNode -> next;
} // end else
} // end while
if (searchNode == aLinkList.head)
{
newNode -> next = searchNode;
newNode -> prev = NULL;
searchNode -> prev = newNode;
aLinkList.head = newNode;
} // end if
else
{
if(searchNode == NULL)
{
newNode -> prev = searchNode -> prev;
newNode -> next = searchNode;
} // end if
else
{
newNode -> prev = searchNode -> prev;
newNode -> next = searchNode;
searchNode -> prev = newNode;
} // end else
} // end else
newNode -> next = searchNode;
newNode -> prev = searchNode -> prev;
searchNode -> prev = newNode;
} // end else
aLinkList.counter++;
success = true;
} // end else
} // end if
else
{
cout << "No more heap memory. No more integers from the list will be";
cout << " stored." << endl;
success = false;
} // end else
return;
} // end function
bool isEmptyList(topAndCounter& aLinkList)
{
if (aLinkList.head == NULL)
{
return true;
}
else
{
return false;
}
} // end function
