i have a trouble with the files's read on c

Question

2.00/5 (1 vote)

See more:

i wish to read a matrix from a external file but i just don't know that , please help me , i got this code, and the output doesn't is the output that i'm expected

C#

#include <stdio.h>
#include <stdlib.h>

/*
 *
 */



int main(int argc, char** argv) {

 FILE * f;
 int i,j,dimension=5;
 int  adjacency [dimension][dimension];
f = fopen("adjacency.dat", "r");
for(i = 0; i < dimension ; i++){
    for(j = 0; j < dimension; j++){
        fscanf(f, "%d", &adjacency[i][j]);
        }
    }
fclose(f);

printf("matriz de adyacencia \n");

for (i=0;i<dimension;i++){
    for(j=0;j<dimension;j++)
        printf("%d",adjacency[i][j]);
    printf("\n");
}
    return (EXIT_SUCCESS);
}

Posted 4-May-11 17:55pm

rsuez93

Add a Solution

1 solution

Add a Solution

Add your solution here

Treat my content as plain text, not as HTML

Preview 0

…

Existing Members

Sign in to your account

...or Join us

Download, Vote, Comment, Publish.

Your Email
Password
Forgot your password?

Your Email
This email is in use. Do you need your password?
Optional Password

I have read and agree to the Terms of Service and Privacy Policy
Please subscribe me to the CodeProject newsletters

When answering a question please:

Read the question carefully.
Understand that English isn't everyone's first language so be lenient of bad spelling and grammar.
If a question is poorly phrased then either ask for clarification, ignore it, or edit the question and fix the problem. Insults are not welcome.
Don't tell someone to read the manual. Chances are they have and don't get it. Provide an answer or move on to the next question.

Let's work to help developers, not make them feel stupid.

This content, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)

tolw · Answer 1 · 2011-05-04T19:56:00

Solution 1

The code should not even compile let alone do anything as expected :)
The first thing is the array declaration. This:

int  adjacency [dimension][dimension];

should give an error ('expected constant expression' or something like that). If you want to be able to change the size of the array you can either use a define:

#define DIM 5
...
int adjacency [DIM][DIM];

or use the 'new' operator to create the array.

As for the file reading - you should probably post the contents of the file - otherwise there's no way to know what you are trying to read.

I would also suggest checking if the file was oppened correctly before reading anything...

if( f != NULL )

Posted 4-May-11 19:56pm

tolw

Comments

rsuez93 5-May-11 2:03am

I fixed it all , the problem is the output, i have a problem on the read's data from the file ( which have a 3*3 matriz of numbers

tolw 5-May-11 2:26am

Can you post the file contents? Just to see what you are dealing with.
Also if the file has a 3x3 matrix of numbers and the array is 5x5 as in your example - you have too few numbers

rsuez93 5-May-11 2:33am

the file is matriz.txt wich contains a 3x3 matriz : 123
456
789

i want to read these values and stored in a program's matrix, i don't know if the error thah i have it's cuz is there an error when the program reads the file, the thing it's that

when the program runs, the output matrix it's just like this: 1234562425235626
4223523532562632

tolw 5-May-11 2:48am

Are the values space separated? If not than the first number read would be 123 instead of 1... You should try debbuging to look at the array contents - what's the first number you read?

Try putting this into your file:
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24

EDIT: Also, try setting the array cells to 0 before reading anything:
memset( array, 0, sizeof( array) );