Recursion

Quote:

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Originally Posted by hyperx

Ya. U R exactly right. If going right and down I can get it correctly. But left and up it will be reversible. Assuming I choose ABC, for left and down or should I say decrement it would be CBA. Is there anyway I can fix it.

Can u xplain more on "index of sorts to keep track of which character you are using, and wrap it as required". I'm not clear about that.

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Sort of like this (for the wrapping).

Code:

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char array[] = "ABC";
int index = 0;

putchar(array[index]);  /* A */

index --;
if(index < 0) index += 3;
putchar(array[index]);  /* C */

index ++;
if(index >= 3) index -= 3;
putchar(array[index]);  /* back to A again */

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Quote:

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Originally Posted by dwks

Sort of like this (for the wrapping).

Code:

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char array[] = "ABC";
int index = 0;

putchar(array[index]);  /* A */

index --;
if(index < 0) index += 3;
putchar(array[index]);  /* C */

index ++;
if(index >= 3) index -= 3;
putchar(array[index]);  /* back to A again */

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IC, now I'm a little bit confuse to adapt it to my code. I think I should rest first. It's 3 am right now. Maybe tommorow I'll will work on it. Thanks dwks. If I have a problem on getting into this code again I'll ask you. Ok. Thank you very much.

This code

Code:

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index --;
if(index < 0) index += 3;
putchar(array[index]);  /* C */

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shows you how to handle going left, and the ++ part shows you how to handle going right.

You could use it like so:

Code:

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void fill(int x, int y, char *a, int index, int i)
{
  if ((screen[x][y] != ' ')|| (x > 65))
    return;
  if(index < 0) index += a_max;
  if(index >= a_max) index -= a_max;
 
  screen[x][y] = *a;
 
  a++;
  if(*a == '\0')
          a-=i;
  fill(x+1,y,a,index+1,i);
  fill(x-1,y,a,index-1,i);
  fill(x,y-1,a,index,i);
  fill(x,y+1,a,index,i);
}

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a_max is the number of characters in a. You could use strlen() for it.

Quote:

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Originally Posted by dwks

This code

Code:

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index --;
if(index < 0) index += 3;
putchar(array[index]);  /* C */

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shows you how to handle going left, and the ++ part shows you how to handle going right.

You could use it like so:

Code:

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void fill(int x, int y, char *a, int index, int i)
{
  if ((screen[x][y] != ' ')|| (x > 65))
    return;
  if(index < 0) index += a_max;
  if(index >= a_max) index -= a_max;
 
  screen[x][y] = *a;
 
  a++;
  if(*a == '\0')
          a-=i;
  fill(x+1,y,a,index+1,i);
  fill(x-1,y,a,index-1,i);
  fill(x,y-1,a,index,i);
  fill(x,y+1,a,index,i);
}

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a_max is the number of characters in a. You could use strlen() for it.

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The function still not work correctly. It print, but it print randomly not in sequence. The problem right just going left. If I remove fill(x-1,y,index-1,i) then it worked correctly but it not printing to the left. Hurm... a bit tough...... But i will try until succeed. Do you have any other idea.

Do a full range check on x and y

if ( x < 0 || x >= XMAX || y < 0 || y >= YMAX ) return;

Quote:

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Originally Posted by Salem

Do a full range check on x and y

if ( x < 0 || x >= XMAX || y < 0 || y >= YMAX ) return;

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I've done the full range check but still not working properly. It print character randomly. not in sequence.

I'd rather not have to reconstruct the code you have from the snippets you've posted, so you'll just have to post your latest code.

Quote:

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Originally Posted by Salem

I'd rather not have to reconstruct the code you have from the snippets you've posted, so you'll just have to post your latest code.

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Code:

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

#define XMAX 65
#define YMAX 32

char screen[XMAX][YMAX];

void printScreen(void);
void fill(int, int, char*,int, int);

int main(int argc, char *argv[])
{ FILE *in;
  int x, y;
  char *a;
  int ArraySize, index = 0;

  if (argc!= 5)
  { fprintf(stderr,"Usage:\n\t&#37;s <65x32 text file> <x> <y> <sentences>\n",argv[0]);
    exit(1);
  }

  in = fopen(argv[1],"r");
  if (in == NULL)
  { perror("opening input file");
    exit(1);
  }

  for (y=0; y<YMAX; y++)
  { for (x=0; x<XMAX; x++)
      screen[x][y] = fgetc(in);
  }
  if (fclose(in))
  { perror("closing input file");
    exit(1);
  }


  x = atoi(argv[2]);
  y = atoi(argv[3]);
  a = argv[4];

  ArraySize = strlen(a);
  while (a[ArraySize] != 0)
          ArraySize++;
  fill(x,y,a,index,ArraySize);
  printScreen();
}

void printScreen (void)
{ int x,y;
 
  for (y=0; y<YMAX; y++)
      for (x=0; x<XMAX; x++)
          if(screen[x][y]!= EOF)
              putchar(screen[x][y]);
                  else               
              puts("\n");       
}

void fill(int x, int y, char *a,int index, int i)
{
  if (screen[x][y] != ' ')
    return;
   
  screen[x][y] = *a;
 
  if((x < 0)||(x>65)||(y<0)||(y>32))
          return;

  if(index < 0) index += strlen(a);
  if(index >= strlen(a)) index -= (strlen(a));
 
  screen[x][y] = *a;
 
  a++;
  if(*a == '\0')
          a-=i;
  fill(x+1,y,a,index+1,i);
  fill(x-1,y,a,index-1,i);
  fill(x,y-1,a,index,i);
  fill(x,y+1,a,index,i);
}

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Here's my latest code but still didn't work correctly.