# Thread: Homework help?

1. ## Homework help?

So the beginning numbers are laid out like this:
8 0 3 6 3
1 3 1 0 7
2 7 9 4 5
Then I have to print it out to look like:
3 6 3 0 8
7 0 1 3 1
5 4 9 7 2.
This is what I have so far, and i know its not right because i keep getting an error that the program has quit working.
Code:
```void
copyB(const int *fromPtr, int rows, int columns, int to[][10])
{
int r;
int c;

for (r =  columns -1; r < rows; r--) {
for (c = 0; c < columns; c++)
to[r][c] = *fromPtr++;
}
}```
This is not my major I technically dont even need this class anymore since i switched majors but i dont want to drop it now, so any tips are appreciated. I have to run it against my professors test driver, but i just can get this one to work right.
Thanks for any help!

2. You don't need to copy it.
Just swap the n'th element of each row with the (columns -n)'th element.(...iterating n over 0 to columns )

3. Well with the example you showed the function should not do anything. If columns is 5 and rows is 3, then r would = 4. When you enter the for loop, r is not less than rows.

4. easy! This code works....
Code:
```#include<iostream.h>

void main()
{ int c[3][5];
for(int i=0;i<3;i++)
for(int j=0;j<5;j++)
cin>>c[i][j];

for(i=0;i<3;i++)
{for(int j=4;j>=0;j--)
cout<<c[i][j];
cout<<endl;}
}```

5. @ Amin sma
Note that we're here to help people figure out the answer for themselves.
Not show off by dumping the complete answer at the first opportunity.

6. Which, mind you, doesn't even compile on standard-compliant compilers!

7. That solution is wrong in at least three different ways. For starters it should not use a two-dimensional array when a plain 1D array is sufficient.

8. ok

9. Originally Posted by iMalc
That solution is wrong in at least three different ways. For starters it should not use a two-dimensional array when a plain 1D array is sufficient.
True, but his array is to[c][r]. You know how it is teachers are always allowed do things like that. ;-)

10. Originally Posted by überfuzz
True, but his array is to[c][r]. You know how it is teachers are always allowed do things like that. ;-)
I'm assuming that the decision of the function prototype is his own, and so could be whatever. Afterall, it's doing such a trivial task (reversing an array) that I would not even create a function for it.
Just read in each line and then print it out backwards. Amin got that part right, albeit with missing formatting.

11. Originally Posted by iMalc
Afterall, it's doing such a trivial task (reversing an array) that I would not even create a function for it.
It could pass as an exercise in the array part in some course. Ah well...

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