I need an algorithm.... please help

**darcome** · 03-14-2003

I need an algorithm who can create strings which are like

a
...
...
z
aa
....
...
za
ab
....
...
zb
ac
...
zz
aaa
....
.....

like a brute force.

Do you know the name of this algorithm, so i can search through the net for an optimized version?

I made such an algorithm, but i think it is slow, so i'm searhing for an optimized version.

Please help me

**Yawgmoth** · 03-14-2003

How bout posting your code so we can give you some optimization tips?

**darcome** · 03-14-2003

I am rewriting it, I think tomorroe (3-15-2003) I'll post what I coded

**darcome** · 03-14-2003

Here it is:

Code:

	int i;
//	char charset[] = "abcdefghijklmnopqrstuvwxyz0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ";
	char CharSet[] = "abc";
                char string[50];
	int PosCharSet[50]; // for every character of the string it is a "pointer" to the letter of the charset

	min = 0;
	max = sizeof (CharSet) - 2;

                memset (&string, 0, sizeof (string));

	for (i = 0; i < 50; i++)
		PosCharSet[i] = 1;

	for (;;)
	{
		for (i = min; i <= max; i++)
		{
			string[0] = CharSet[i];
                                                printf (string);
		}

		i = 1;

		while (string[i] == CharSet[max])
		{
                                                string[i] = CharSet[min];
			PosCharSet[i] = 1;
			i++;
		}

		if (string[i] == NULL)
		{
			string[i] = CharSet[min];
			PosCharSet[i] = 1;
		}
		else
		{
			string[i] = CharSet[PosCharSet[i]];
			PosCharSet[i]++;
		}

Tell me what you think about it, and if you know another way to make it, tell me, I don't want an optimized version of my algorithm only, if there is a different algorithm, which does what I need and it is faster, write it

Thank you for your help, waste of time and patience

**Scarlet7** · 03-15-2003

Here's some code which may do what you want. Change MAX_LEN for the code length i.e. MAX_LEN 3 will give 'a' to 'zzz'

Code:

#include <stdio.h>

int GetNextCode(char* c, int max)
{
     for(int i = 0; i < max; i++)
     {
          if(!c[i])
          {
               c[i] = 'a';     
               return 1;
          }

          if( c[i] < 'z' )
          {
               c[i]++;
               return 1;
          }
          else
               c[i] = 'a';     
     }
     return 0;     
}

#define MAX_LEN 3
int main()
{
     char code[MAX_LEN + 1] = {0};

     while( GetNextCode(code, MAX_LEN) )
          printf("%s ", code);

     return 0;
}

**darcome** · 03-16-2003

hank you very much for your help guys

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