Member Avatar for Nakeo

I have finished writing a program that uses Linked lists and reads in input from a txt file. When the program executes there is no output. I have been going through the code for awhile now and there are no syntax errors and i can not seem to find what is causing it to not display the right output. Since my the code is a little long and i do not know where the problem is I will just attach the source code, the txt file and some information about the program. If anyone is kind enough to look through it and point me in the right direction that would be awesome.

prog2.txt

prog2.cpp

info.doc

info.doc (18.5 KB) 
// Matt Smith 274
// Assignment:Program 2 Due: 3/22/10
// Purpose: The program will read in data on motorcycles and and perform functions
// on them based on the commands read in from the data file

#include <iostream>
#include <iomanip>
#include <string>
#include<fstream>
using namespace std;

struct Motorcycles
{
string Model;
int StockNum;
string Style;
double price;
int hp;
Motorcycles *nextNode;
};

//Global Variables
ifstream infile;

//Function Prototypes
Motorcycles *CreateMotorcycle();
Motorcycles *AddToModel(Motorcycles *firstBike, Motorcycles *newMotorcycle);
void PrintList(Motorcycles *firstBike);
void SellOneBike(Motorcycles *&firstBike);
void PriceList(Motorcycles *firstBike);
void StyleList(Motorcycles *firstBike);
void ManuList (Motorcycles *firstBike);

//Main function
int main()
{
	Motorcycles *firstBike;
	firstBike = NULL;
	Motorcycles *newMotorcycle;
	infile.open("prog2.txt");
	newMotorcycle = new Motorcycles;
	int command = 0;

	
	while (!infile.eof())
	{
		infile>>command;
		if(command != 7)
		{
			if(command == 1)
			{
			newMotorcycle = CreateMotorcycle();
			firstBike = AddToModel(firstBike, newMotorcycle);
			}
			else if(command == 2)
			{
			SellOneBike(firstBike);
			}
			else if(command == 3)
			{
			PrintList(firstBike);
			}
			else if(command == 4)
			{
			PriceList(firstBike);
			}
			else if(command == 5)
			{
			StyleList(firstBike);
			}
			else if(command == 6)
			{
			ManuList(firstBike);
			}
		}
	}
	infile.close();
	return 0;
} 

Motorcycles *CreateMotorcycle()
{
	Motorcycles *newNode = NULL;
	

	newNode = new Motorcycles;
	getline(infile,newNode->Model); 
	infile >> newNode->StockNum; 
	getline(infile,newNode->Style);
	infile.ignore();
	infile >> newNode->price >> newNode->hp;
	newNode->nextNode = NULL;

	infile.ignore();

	return newNode;
}
Motorcycles *AddToModel(Motorcycles *firstBike, Motorcycles *newMotorcycle)
{
	Motorcycles *tptr = NULL;

	tptr = firstBike;
	
	
	if(!firstBike)
	    firstBike = newMotorcycle;
    else
    {	tptr = firstBike;
	    while(tptr->nextNode)
		    tptr = tptr->nextNode;
        tptr->nextNode = newMotorcycle;
    }
	return firstBike;
}
void PrintList(Motorcycles *firstBike)
{
	cout << left;
			cout << "-------------------------------------------------" << endl;
			cout << setw(20) << "Model" << setw (10) << " Stock Num"
			<< setw(10) << "Style" << setw (10) << "Price" 
			<< setw (10) << "HP" << endl;
	Motorcycles *tptr = firstBike;

    if(!tptr)
        cout << "The list is empty" << endl;
    else 
    {
        cout << "The Bike List" << endl;
        cout << "*************" << endl;
        while (tptr)
        {	
			cout << setw(20) << tptr->Model << setw (10) << tptr->StockNum
			<< setw(10) << tptr->Style << setw (10) << tptr->price 
			<< setw (10) << tptr->hp << endl;
	        tptr = tptr->nextNode;
        }
        cout << "*************" << endl;
    }
}
void SellOneBike(Motorcycles *&firstBike)
{
	Motorcycles *nodePtr;       // To traverse the list
    Motorcycles *previousNode;  // To point to the previous node
	double stockid = 0;

	infile >> stockid;

   // If the list is empty, do nothing.
   if (!firstBike)
   {  
	   cout << "The list is empty" << endl;
	   return;
   }
      // Determine if the first node is the one.
   if (firstBike->StockNum == stockid)
   {
      nodePtr = firstBike->nextNode;
      delete firstBike;
      firstBike = nodePtr;

   }
   else
   {
      // Initialize nodePtr to head of list
      nodePtr = firstBike;

      // Skip all nodes whose value member is 
      // not equal to num.
      while (nodePtr != NULL && nodePtr->StockNum != stockid)
      {  
         previousNode = nodePtr;
         nodePtr = nodePtr->nextNode;
      }
      // If nodePtr is not at the end of the list, 
      // link the previous node to the node after
      // nodePtr, then delete nodePtr.
      if (nodePtr)
      {
         previousNode->nextNode = nodePtr->nextNode;
         delete nodePtr;
      }
 
   }
}
void PriceList(Motorcycles *firstBike)
{
	Motorcycles *Tptr;
	Tptr = firstBike;
	double pricelist;

	infile>>pricelist;

	if (!firstBike)
   {  cout << "The list is empty" << endl;
      return;
   }

	while(Tptr)
	{
		if(Tptr->price <= pricelist)
		{
			cout << setw(20) << Tptr->Model << setw (10) << Tptr->StockNum
			<< setw(10) << Tptr->Style << setw (10) << Tptr->price 
			<< setw (10) << Tptr->hp << endl;
		}
		Tptr = Tptr->nextNode;
	}
}
void StyleList(Motorcycles *firstBike)
{
	Motorcycles *Tptr;
	Tptr = firstBike;
	string stylelist;

	infile>>stylelist;

	if (!firstBike)
   {  cout << "The list is empty" << endl;
      return;
   }

	while(Tptr)
	{
		if(Tptr->Style == stylelist)
		{
			cout << setw(20) << Tptr->Model << setw (10) << Tptr->StockNum
			<< setw(10) << Tptr->Style << setw (10) << Tptr->price 
			<< setw (10) << Tptr->hp << endl;
		}
		Tptr = Tptr->nextNode;
	}
}
void ManuList (Motorcycles *firstBike)
{
	Motorcycles *Tptr;
	Tptr = firstBike;
	double sum = 0, avg = 0, count = 0;
	int index = 0;
	string manu, currentManu;

	infile >> manu;

	while(Tptr)
	{
		while (Tptr->Model[index] != ' ' && index < int(Tptr->Model.size()))
            index++;
        currentManu = Tptr->Model.substr(0, index);
		if(currentManu == manu)
		{
			cout << setw(20) << Tptr->Model << setw (10) << Tptr->StockNum
			<< setw(10) << Tptr->Style << setw (10) << Tptr->price 
			<< setw (10) << Tptr->hp << endl;

			sum+= Tptr->hp;
			count++;
		}
		Tptr = Tptr->nextNode;
	}
	avg =sum/count;
	if(avg>0)
		cout << "The average Horse Power is " << avg << endl;
}
2 1010
1Honda RC51
1232
Super
9895.95 125
2 1232
2 1232

1Suzuki GSXR750
2134
Super
6395.95 110

1Yamaha V-Star1100
4892
Cruiser
7458.95 123

1Harley VRod1300
1321
Cruiser
23855.95 92

1Suzuki Katana600
8873
Sport
4593.95 87

1Honda SuperHawk
3971
Sport
5789.95 105

1Harley VTR100
5372
Super
12393.95 135

1Honda NightHawk
4725
Moto GP
3494.95 79

1Yamaha V-Max1200
9421
Street
8794.95 112

1CBRF4i600
6722
Sport
6785.95 95

1Harley Big Dog
7923
Moto GP
17828.95 88

1Suzuki GS850
7319
Street
2395.95 75

1Honda GoldwingGL1500
3412
Cruiser
14959.95 93

1Harley FLHR
9347
Cruiser
12939.95 70

1Suzuki Intruder1400
6895
Cruiser
8737.95 110
3
4 8000.00
4 10000.00
4 1000.00
5Super
5Cruiser
5Moto GP
6Yamaha
1Yamaha YZF-R1
1110
Super
9388.95 125
3
1Yamaha YZF-R6
9982
Street
5896.95 90
3
6Yamaha
6Kawasaki
6Indian
2  4725
2  5555
2  9982
1Kawasaki Ninja1200Z
8885
Super
12896.95 131

3
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  • 1 Reply
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  • 6 Hours Discussion Span
  • Latest Post Latest Post by Jiwe
Member Avatar for Jiwe

Your not reading the txt file to the structure so the pointer to the structure will always be null and never execute anything your just reading the command nothing else.

Try to learn how to write and read structures to file. Methods read() and write().

Hope it helped.

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