need some help with C programming - PeachParts Mercedes-Benz Forum

TheDon · #1 03-09-2010, 12:41 AM

again.. lol

So I need to use file I/O to take in some data and use it to output something...

taking in golf scores and the number of golfers.. example input

2 (number of golfers
1 2 3 4 5 x x x x x ( par)
2 3 4 4 4 (golfer 1 score)
3 4 4 2 1 (golfers 2 score)

number of golfers allowed for the program is golfers <=100.

I already did a program that takes in all that info and out puts the golfers over/under score.

so now I need to do the same thing but output it for each hole.

ex

Golfer 1 score : -1 0 1 2 -2 1 0 0
etc etc etc

so, I am thinking I can use a majority of the the code from the previous program but use arrays in some fashion to get the desired output but cannot think how to do it.

take note this is in C not C++

300SD81 · #2 03-09-2010, 01:09 AM

excuse my lack of golf knowledge.. is the number of holes fixed? If it is, I would malloc a 2-dimensional array, have a seperate array for par, and loop through doing the math. If not, then calculate the size of the arrays first from the number of holes...

TheDon · #3 03-09-2010, 01:15 AM

well here is the sample input file I have to use to test my programs

2
3 4 4 4 4 5 5 3 3 4 4 4 4 4 5 3 3 4
4 4 5 4 6 4 5 6 3 4 4 4 5 4 3 3 5 4
2 3 4 4 4 5 5 3 3 4 4 4 4 4 4 3 3 4

just an example.. first line of scores is par and the consecutive lines are the scores of golfers. Of course the number of holes are fixed.. lol this is for an round of golf with 18 holes.

how would I take in the array?...

fscanf(Fin,"%d",&par[18]);

?

300SD81 · #4 03-09-2010, 01:30 AM

I'd do something like this, codes a mess and does no error checking, but you get the idea.

Code:

int main (...) {
	
...

	int numgolfer = (fgetc(stdin) - '0'); //convert ascii to int
	
	fgetc(stdin); // ignore newline
	
	int* par = malloc(18*sizeof(int));
	int* scores = malloc(numgolfer);

	for (int i = 0; i < numgolfer; i++) {
		scores[i] = malloc(18);
		for (j = 0; j<18; j++) {
			//read scores in
		}

	}
}

I'm not as good with strings as with bytes in C... basically all my experience with C the past couple years has been with microcontrollers.

OldPokey · #5 03-09-2010, 12:38 PM

Code:

FILE *fp;
char line[128], *pTok, *pStr;
int golfers, par[18], scores[100][18];
int ii, golferIndex;

fp = fopen ( "foo", "r" );

/* Read in number of golfers */
if ( fgets ( line, sizeof(line), file ) != NULL )
{
    sscanf ( line, "%d", &golfers );
}
else
{
    golfers = 0;
}

/* read in par line */
if ( fgets ( line, sizeof(line), file ) != NULL )
{   
    pStr = line;
    for ( ii = 0; ii < 18; ii++ )
    {
        /* Grab them one token at a time */
        pTok = strsep ( &pStr, " " );
        if ( pTok == NULL || !sscanf ( pTok, "%d", &par[ii] ) )
        {
            break;
        }
    }
}

/* Read in scores */
golferIndex = 0;
while ( golferIndex < golfers && fgets ( line, sizeof(line), file ) != NULL )
{
    pStr = line;
    for ( ii = 0; ii < 18; ii++ )
    {
        /* Grab them one token at a time */
        pTok = strsep ( &pStr, " " );
        if ( pTok == NULL || !sscanf ( pTok, "%d", &scores[golferIndex][ii] ) )
        {
            break;
        }
    }
    
    golferIndex++;
}

fclose ( file );

strsep() lets you tokenize a string in loop fashion. For more info on that google "man strsep". There are tons of helpful library routines - if you can think of something basic you need to do, it's probably in the standard C library.

Now you have the scores in a two-dimensional array. Go through it a golfer at a time (first dimension) and do the math for each hole (second dimension).

TheDon · #6 03-09-2010, 08:42 PM

interesting..

fgets.. what is that?

if its what It hink it is we were told to never use "gets" in any form or fashion.. its just bad juju

Matt L · #7 03-09-2010, 08:46 PM

What system are you using? If it's Linux or UNIX, you have manual pages. If it's Windows, you have MSDN.

TheDon · #8 03-09-2010, 08:48 PM

uhm.. its on a winders machine compiling in DEV C++

Matt L · #9 03-09-2010, 11:23 PM

http://www.google.com/search?q=msdn+fgets&ie=utf-8&oe=utf-8&aq=t&rls=org.mozilla:en-US

fficial&client=firefox-a

OldPokey · #10 03-10-2010, 04:14 PM

Using gets() is bad juju because there is no limit to how much data it can suck in. This can lead to overflow errors. The fgets() function has a limit, which is the second argument - the sizeof(line) statement. It's perfectly safe to use, and in fact should be used instead of gets().

TheDon · #11 03-10-2010, 06:56 PM

so I'd use the

"char *fgets(
char *string,
int n,
FILE *stream
);
wchar_t *fgetws(
wchar_t *string,
int n,
FILE *stream
);"

in each arguement to take in the par score then the succesive scores for each golfer n?

TheDon · #12 03-10-2010, 07:05 PM

i dont know what the hell to do.. really.. I dont

Matt L · #13 03-10-2010, 08:40 PM

I suspect that you should be using fscanf to read the numbers.

Too bad you're not learning FORTRAN. It has language constructs to do this very thing.

TheDon · #14 03-10-2010, 09:11 PM

yes.. I know i am using fscanf.. but I need it to output with the over/under score for each hole... which is where I think I will need arrays but i dont know what to do in regards to that

Matt L · #15 03-10-2010, 09:54 PM

Yes, some arrays would be appropriate here. Have you tried searching Google for tutorials? Lots of stuff is out there for the finding.

You'll want to use fscanf in a loop to read each number into the appropriate array.