Thread: Large 1D array -> Grid-like 2D array. HOW?

Hello.

Im making a game for a certain community and I can load in these map levels. Each level is exactly 592 bytes -

30x20 (30 chars to the right, 20 down) + end of line char and '\n' char. Oh but hte last line is the password for hte level so its only 4x20 if it wree gridded.

Anyways, Im trying to grid it like that in a 2D array. My function:

Code:

void WorkWithMap() {
     for(i=0;i<19;i++) {
                       for(z=0;z<30;z++) {
                                         
                                         level[i][z]=map[i*z];
                                                                             
                       }
     }
}

I dont WANT the password in there, so i didnt read up to 20 (hence i<19). This way doesnt work as when printing out, its all random and multiple characters where there is only one of in the file. So... Please help?

I believe one reason is because if

i=0

and z=... say...

z=23

Than

level[i][z] = map[ 0 * 23 ]

thus resulting in map[0] through out the entire thing... Any way to make it work?

You're doing your math wrong. Your entire first row will be multiplied by zero. As will your entire first column. You need something like:

Code:

level[i][z] = map[ i + (z * 19) ];

Quzah.

Yep. So switch it around. Do you understand what it is you do to make a single dimension array act like a two dimensional one? You need to simulate each row and column. Therefore, you need to index each column. You need to also index each row.

The column you're on is simply the column counter. Add that to your row. Your row is the length of each row, multiplied by your current row counter.


Quzah.

Originally Posted by SG57

Im still having problems with it. I can get it to display like this:
Can someone confirm a working way to do this? I undrstand what you said and whatnot, but its just not working when i try.

Perhaps because you're using end of line char's, and newline char's. They'll just goof it up, you need to get them out of there, or account for them in your arithmetic.

Hint: get rid of them.

My puzzle/game programs just about all use 2d and 1d arrays, and swap back and forth. There is no problem if you don't have extra char's in the array.

Here's an example:

Wheels is a 1D array. SATemp is a 2D array, and I'm transferring the SATemp data into the Wheels array:

Wheels[r * 10 + c] = SATemp[r, c]

Where r = row number, c = column number, and each row has 10 squares (this is from a Sudoku game). Wheels was an odometer graphic for solving the puzzle by brute force. SATemp was the Sudoku Array (Temp), the working array at that time.

As you know, Sudoku standard puzzles just have 9 ssquares, but I have 10 sqr's in my array, and don't use the zero, 10, 20, 30, etc., sqr's for anything. They're not shown at all. The size just helps with the coding.


Adak

It works, guy! I use that code in my chess program, my Sudoku program, my minesweeper program, etc.

It's just simple arithmetic, but you do need to ditch the extra char's - newlines, end of line markers, etc. At least until you get the basic one D to two D array changeover, working.

Did you do that, yet?

I'm just guessing here, but I'll bet money that you had your code to not transfer over certain char's into the new array - and THEN you forgot to subtract your array index number to account for that non-additional char. That's why you have 1 blank in the final array, every row or so.

The reason it's frustrating is that you're telling the Wright brothers, that their flyer won't get off the ground. And we've already flown it in North Carolina, Paris, U.K., Germany, Ireland, etc.

Your code snippet didn't include all the details needed to give you a more detailed answer for your particular program, but what I posted - definitely "flies".

If you have another problem, then you need to post the code showing it, and describe it in more detail, please.

Adak

SG, that code I posted was STRAIGHT out of a Sudoku game, and it's been solving EVERY standard puzzle correctly for months, now.

Can the newlines and end of line char's be ignored with a simple if statement inside the transfer loop of data from one array to the other?

Code:

for (i = 0; i < (row * rowwidth + col); i++)  {
   value = 1D_array[i];
   if ((value != '\n) && (value != end of line char)) {
       row = i / 10;
       if (row < 1) row = 1;
       col = i % 10; 
       2D_array[row, col] = 1D_array[i]; 
   }
}

It's late and I'm punchy, but the above should give you some idea's.

I'm off for some zzzz's. Good luck. I'll check back tomorrow. Still stuck, post or pm me, and show EXACTLY what is is that you have, and what it is that you want.

A few rows of stars isn't too challenging.

I believe if you change your variables from i, j, k, z, etc., and make them row, col, sqr, (or i for sqr if you're solid with that), you'll start to see how to do this. Maybe try it for just two rows, at first, then make it bigger.

Adak

offset=row*width+column

Since this is more suited to C++ than C:

Code:

class CMap
{
  WORD *m_pMap;
  WORD m_uWidth;
  WORD m_uMaxOffset;

  public:
   CMap():m_pMap(NULL),m_uWidth(0),m_uMaxOffset(0) { }
   virtual ~CMap(void) { delete [] m_pMap; }

   bool Create(int iWidth,int iHeight)
   {
      m_uMaxOffset=iWidth*iHeight;
      m_pMap=new WORD[m_uMaxOffset];

      if (!m_pMap) return true;

      m_iWidth=iWidth;
   }

   WORD GetValue(int iRow,int iCol,bool &bResult)
   {
      WORD uOffset=iRow*m_uWidth+iCol;
      if (uOffset>m_uMaxOffset) 
      {
         bResult=true;
         return 0xFFFF;
      }
      bResult=false;
      return m_pMap[uOffset];
   }

   bool SetValue(int iRow,int iCol,WORD uValue)
   {
     WORD uOffset=iRow*m_uWidth+iCol;
     if (uOffset>m_uMaxOffset) return true;
     m_pMap[uOffset]=uValue;
     return false;
   }
};

Convert to C and you have your map.

The map you posted looks like it's 19x29, so assuming a newline character was read at the end of every line, maybe this would work:

Code:

     j=0;
     for(i=0; i<19; i++) {
                       for (z=0; z<30; z++) {
                                         if (z != 29) {
                                                     level[i][z] = map[j];
                                         }
                                         j++;
                       }
     }