How to read in text file

[TommehTGOD]

writing a program where i have to read in grade and credit hour values to calculate gpa.

this is my input txt file
ID# Grade cr hrs Grd cr hrs Grd cr hrs Grd cr hrs Grd cr hrs
30713 4 3 3 4 3 3 2 3 4 3
21356 4 4 4 3 3 3 2 3 2 3
21265 4 1.5 3 3 3 0.5 2 3 3 3
19364 4 3 3 3
19335 0 3 0 4 2 3 3 1.5
18264 2 3 3 0.5 3 0.5 3 3 2 3
20135 4 1 3 4 3 1.5 0 3
22185 4 3 4 4 4 3 3 3 4 3

this is how it looks in the input file on c++

30713 4 3 3 4 3 3 2 3 4 3
21356 4 4 4 3 3 3 2 3 2 3
21265 4 1.5 3 3 3 0.5 2 3 3 3
19364 4 3 3 3 -1 -1 -1 -1 -1 -1
19335 0 3 0 4 2 3 3 1.5 -1 -1 
18264 2 3 3 0.5 3 0.5 3 3 2 3
20135 4 1 3 4 3 1.5 0 3 -1 -1 
22185 4 3 4 4 4 3 3 3 4 3

the -1's are the sentinel values, where when it reads -1, the loop ends inside my while loop and moves to the next line.

How DO i read in grade and credit hours for each course
is it like this??
infile>>ID>>grade>>crhrs>>grade>>crhrs>>grade>>crhrs>>grade>>crhrs>>grade>>crhrs;

[liquidfuzz]

Is it a big file, do you have to make it efficient or just working?

check out this in the reference:
fstream - to handle your file
getline - to read line by line
push_back - build a vector with data. (ok but slow if you run many.)

[TommehTGOD]

i mean it reads in, but my professor told me the way i'm reading it in needs to be changed (i guess)

because for example
30713 4 3 3 4 3 3 2 3 4 3
30713 represents the ID
the first 4 represents the grade
the first 3 represents the credit hours (crhrs)
then the next 3 represents the grade
and the next 4 represents the credit hours (crhrs)
etc, etc.'

I think that needs to be changed...how to read that in correctly, I have to calculate the gpa with this. my professor there's some type of loop where it can read a VARYING number of items in a record, but i don't know what loop it is..
this is what i have so far in my code

int main()
{
	double gpa, points, hours, ID, grade, crhrs;

	ofstream OutputFile;
	OutputFile.open("Output.dat");

	ifstream infile;
	infile.open("Input.dat");

	OutputFile<<setw(30)<<"Thomas Powe"<<endl;
	OutputFile<<setw(29)<<"03-27-12"<<endl<<endl;
	OutputFile<<setw(15)<<"ID"<<setw(18)<<"GPA"<<endl<<endl;
	infile>>ID>>grade>>crhrs>>grade>>crhrs>>grade>>crhrs>>grade>>crhrs>>grade>>crhrs;
while (!infile.eof() && grade <= -1)
	{
	//infile>>ID>>grade>>crhrs>>grade>>crhrs>>grade>>crhrs>>grade>>crhrs>>grade>>crhrs;
	//OutputFile<<setw(15)<<ID<<setw(18)<<"Comin Soon"<<endl;
	points = (grade * crhrs) + (grade * crhrs); //+ //(grade * crhrs); //+ (grade * crhrs) + (grade * crhrs);
	hours=crhrs + crhrs; //+ crhrs +crhrs +crhrs;
	gpa=points/hours;
	infile>>ID>>grade>>crhrs>>grade>>crhrs>>grade>>crhrs>>grade>>crhrs>>grade>>crhrs;
	OutputFile<<setw(15)<<ID<<setw(18)<<gpa<<endl;
	}
	OutputFile.close();
	infile.close();
	return 0;
}

[liquidfuzz]

I guess brake the forum codex and spoil your fun if I pass you a solution. But you shouldn't walk away empty handed, right.

I persist, look up getline. Then you need to figure out how to traverse, or maybe iterate with a counter, through the present line.

[TommehTGOD]

i don't think i can use "getline" because we have not learned that yet in class. is there any other way?

[liquidfuzz]

Well my assignment to you is, look up getline. That's the way you will do it starting right after your assignment.

I guess your professor want you to look for special characters in the string. In c++ string is sort of an array with chars. Look for characters like say: '\n' and ' ' in the char array.

[Ebenezer justin]

try this....

while(!infile.eof() )
{
if( grade !=-1)
{
.......
......
.....
}
}
..........