transposing matrix from file to file

This is what I have, but when I run it the file that is printed out has a single number. Can anyone detect anything out of place?

Code:

---

#include <stdio.h>
#define max_row 20
#define max_col 20

int main(void)
{

    int matrix[max_row][max_col];
    int i, j, nr, nc;
   
 
    FILE * input;
    FILE * output;
 
    input = fopen("data.in.txt", "r");
    output = fopen("data.out.txt", "w");
   
    if(!input)
        {
                printf("failed to open file");
        }
       
        /* read input*/
       
        fscanf(input, "%d%d", &nr, &nc);
    for(i = 0; i < nr; i++)
        {
                for(j = 0; j < nc; j++)
                {
                        fscanf(input, "%d", &matrix[i][j]);
                }
        }
               
        /* print transpose in file*/
       
        for(j = 0; j < nc; j++)
        {
                for(i = 0; i < nr; i++)
                {
                        fprintf(output, "%d ", matrix[i][j]);
            }
    return 0;
    }
  }

---

Thanks so much for looking at it.

Quote:

---

Can anyone detect anything out of place?

---

Well, since you didn't actually show us an example of the input... :rolleyes:

Code:

---

if(!input)
        {
                printf("failed to open file");
        }

---

What's the point of even checking to see if the file opened correctly if all you do is continue on regardless?

Now let's see what happens when we learn how to indent properly, shall we?

Code:

---

int main(void)
{
    int matrix[max_row][max_col];
    int i, j, nr, nc;
    FILE * input;
    FILE * output;
 
    input = fopen("data.in.txt", "r");
    output = fopen("data.out.txt", "w");
   
    if(!input)
    {
        printf("failed to open file");
    }
       
    /* read input(even if we have no file to read from...)*/
       
    fscanf(input, "%d%d", &nr, &nc);
    for(i = 0; i < nr; i++)
    {
        for(j = 0; j < nc; j++)
        {
            fscanf(input, "%d", &matrix[i][j]);
        }
    }
               
    /* print transpose in file*/
    for(j = 0; j < nc; j++)
    {
        for(i = 0; i < nr; i++)
        {
            fprintf(output, "%d ", matrix[i][j]);
        }
        return 0;
    }
}

---

Much better.


Quzah.

Sorry my indentation wasn't up to par. I'm not very good at this, obviously.

As for an input, I must have forgotten
it would look something like this:

3 4
1 2 3 5
4 5 6 5
7 8 9 5

It only transposes the first column.

You seem to be missing the point. Your braces is in the wrong place, which is why I colored them for you. What exactly do you think that return statement inside your loop is going to do?


Quzah.

Thanks. I did realize that my braces weren't right. I fixed it, but the program still doesn't do what I'd like it to do. (thanks btw, I probably wouldn't have noticed it.)