Thread: Reading File Help Please!

Hi guys,
I'm still writing programs to read from files, and I really need a little help.

Well I need to read this info
Event task days
1 15 3
1 27 6
1 36 4
2 15 5
3 18 4
3 26 1
4 15 2
4 26 7
4 27 7
5 16 4
My problem is that I need to output to the screen:
1 3
2 1
3 2
4 3
5 1

The first colum list every event, and the next one how many task within the event.
Could you tell me the best way to do this?

Here's my code option 3 is where I'm having problems.
Also my menu selection won't let me go back after selecting an option please could you tell me what I'm doing wrong I will appreciate it
Thank

Code:

#include <fstream>
#include <iostream>
#include <iomanip>

using namespace std;

int main()
{

	int sum(0), icount(1), oldevent(0);
	int count(0),event, next_event, task, next_task, days, max_days;
	char selection;
	bool bstart;
	ifstream cpData;

	
	do	{

		system("cls");  // Clear the screen
		cout << " Dilmer Valecillos CS1600-001  Project # 3 \n\n" << endl;
		cout<< " ---------------------------" ; // Menu Selection
		cout<<" \n | Critical Path Analysis  |\n";
		cout<< " ---------------------------\n\n";
		cout<<" 1 <- Project Completion Timetable  \n" 
			<<" 2 <- Tasks Longer than 5 Days\n"
			<<" 3 <- Task per Event\n"
			<<" 4 <- Quit\n\n";

		cout<< " Choice : ";
		cin.get(selection);


	switch (selection)
	{

		case '1':
			
			system("cls");		
			cout << " Dilmer Valecillos CS1600-001  Project # 3 \n\n" << endl;
			
			cpData.open("cpData.txt"); // To open the file 
		
			if (cpData.fail())
			{
				cout <<" Error opening the file\n";
			}

			else
			{

			cout<<" =============================\n"; // Heading Information
			cout<<" Project Completition Timeable"<< endl;
			cout<<" =============================\n\n";
			cout << " Event   Task   Days\n" << endl;	
		
				if (cpData)
				{
    	
					cpData >> event >> task >> days; // reading from the file
					max_days = days;
			
					do	
					{

						while (! cpData.eof())
						{
							cpData >> next_event >> next_task >> days;
						
							if (event != next_event) 		
							break;

							else if (days > max_days)
							{
								max_days = days;
								task     = next_task;
							
							}
					
						}	
								sum = sum + max_days;
								cout << setw(3) << event <<  setw(8) << task << setw(6) << max_days <<endl;
								event    = next_event;
								task     = next_task;
								max_days = days;
	
					}
						while (! cpData.eof());
						
								cout << "\n The total of Days is:  " << sum << endl;
								cout << " ---------------------"<< endl;
				}
	
				cpData.close();	//close the file 
				system("pause");
	
			break;
					
		case '2':
		system("cls");
		cout << " Dilmer Valecillos CS1600-001  Project # 3 \n" << endl; // Heading info
		cpData.open("cpData.txt"); // Open the CpData File

			if (cpData.fail())
			{
				cout <<" Error opening the file\n";
			}

			else
		
			{	
				cout << "\n Task Requiring more than 5 Days "    << endl; // This is the Heading Information
				cout << " -------------------------------"       << endl;
				cout << "\n\n  Event  " << " Task " << "  Days " << endl;
				cout << "  ----- " << "  ---- " << "  ---- "     << endl;
				cpData >> event >> task >> days ;
 
		
			
				while ( !cpData.eof() ) // keep reading until end-of-file	
				{ 
						cpData >> event>> task >> days; 
			
					if (days > 5  )
					{
						cout << setw(5) << event << setw(8)<< task << setw(7)<< days << endl;
					}
	
				}
						cout << "  ===================\n" << endl;
				
			}

				cpData.close();
				system("pause");
		
				break;
		case '3':
			system("cls");
			cout << " Dilmer Valecillos CS1600-001  Project # 3 " << endl;
			cpData.open("cpData.txt"); 
		
			if (cpData.fail())
			{
				cout <<" Error opening the file\n";
			}

			else
			{
				cout << " \n\n  Number of Tasks per event"  << endl;  // Heading Info
				cout << "  =========================\n"     << endl;
				cout << "  Event " << " Task "              << endl;
				cout << "  ===== " << " ===="               << endl;
		
				cpData >> event >> task >> days;
				oldevent = event;
				count = task;
		
				while (! cpData.eof())// It reads until the last line
				{
		
			
					cpData >> event >> task >> days;
			
					if (bstart == true)	
					{
						icount++;
						oldevent = event;
						bstart = false;
					}
					if ( oldevent == event )
					{
						icount++;
						oldevent = event;
			
					}
			
					else 
					{	
						cout << setw(5) <<oldevent << setw(7) << icount << endl;
						icount = 1;
						oldevent = event;		
					}
			
				}				
			}

			cpData.close();
			system("pause");// Pause to let the user see the output to the screen
			
			break;

		case '\n':

			break;
		case '4':
				system("cls");
				
			break;
		default:
				cout << '\a'; //sound the alarm for invalid input!!
		}
	}while( selection != '4');

	return 0;	
}

Code:

while (! cpData.eof())

You don't read from files like that unless you don't mind infinite loops. Use this format instead:

while(...the read statement here...)

Have you heard of functions yet?

Code:

  selection = ShowMenuAndReadResponse( );
  switch (selection) {
    case '1':
      doProjectTimeTable();
      break;
    // etc etc
  }

> while (! cpData.eof())// It reads until the last line
Actually, it doesn't - it appears to read the last line twice since you fail to do any error checking.
So it fails, and you just re-process the last line over.
See the FAQ for why eof() in a loop construct is bad.