Is This possable? And If so, How?

ID:272258
 
May 17 2008, 1:35 pm
Is it possable to make like, a rand/prob number thing, were the numbers can't be used twice?? And if it is, would anyone mind explaining?
May 17 2008, 1:45 pm
To do this, you would generate a list of numbers, pick from that, and remove what you just picked. It works the same as a deck of cards.
May 17 2008, 4:30 pm
In response to Garthor
Im kinda new at coding so how would I do that? If you dont mind showing, please do.
May 17 2008, 7:33 pm
In response to Garthor
That would easily be quite some extra overhead if you had a big number range; you really don't need a list element per every number from 1 to 100 (for instance) for this, unless you're choosing 100 different numbers. Instead, you should just repeat the rand()/pick()/etc every time is produces a value that was used before (so you'd store past values in a list). You could also possibly optimize it more in some cases so it will do less unneeded processing, but really the above already does the job.

Renjo Kujika wrote:
Im kinda new at coding so how would I do that? If you dont mind showing, please do.

(If you're new to lists, you should read up on them in the DM Reference and DM Guide)
That would be done by creating a list, then calling rand() in a loop, and adding the number it returns to the list only if it isn't already there. You could make a proc for that; 
my_randoms(min,max,num) //this proc takes 3 arguments: first like rand()'s arguments + how many numbers you want.
   var/list/numbers = new //initialize a new list
   while(numbers.len < num) //loop until our list has enough numbers in it
      var/N = rand(min,max) //generate a random number
      if(!(N in numbers)) //if the number isn't already in the numbers list
         numbers += N //add it (also increasing the length of the list in the process)
   return numbers //return the list to the proc caller
May 17 2008, 7:35 pm
In response to Garthor
That would easily be quite some extra overhead if you had a big number range; you really don't need a list element per every number from 1 to 100 (for instance) for this, unless you're choosing 100 different numbers. Instead, you should just repeat the rand()/pick()/etc every time is produces a value that was used before (so you'd store past values in a list). You could also optimize it more in some cases so it will do less unneeded processing, but the above already does the job.

Renjo Kujika wrote:
Im kinda new at coding so how would I do that? If you dont mind showing, please do.

(If you're new to lists, you should read up on them in the DM Reference and DM Guide)
What I said above would be done by creating a list, then calling rand() in a loop, and adding the number it returns to the list only if it isn't already there. You could make a proc for that; 
my_randoms(min,max,num) //this proc takes 3 arguments: first like rand()'s arguments + how many numbers you want.
   var/list/numbers = new //initialize a new list
   while(numbers.len < num) //loop until our list has enough numbers in it
      var/N = rand(min,max) //generate a random number
      if(!(N in numbers)) //if the number isn't already in the numbers list
         numbers += N //add it (also increasing the length of the list in the process)
   return numbers //return the list to the proc caller
May 17 2008, 7:36 pm
In response to Garthor
That would easily be quite some extra overhead if you had a big number range; you really don't need a list element per every number from 1 to 100 (for instance) for this, unless you're choosing 100 different numbers. Instead, you should just repeat the rand()/pick()/etc every time is produces a value that was used before (so you'd store past values in a list). You could also optimize it more in some cases so it will do less unneeded processing, but the above already does the job.

Renjo Kujika wrote:
Im kinda new at coding so how would I do that? If you dont mind showing, please do.

(If you're new to lists, you should read up on them in the DM Reference and DM Guide)
What I said above would be done by creating a list, then calling rand() in a loop, and adding the number it returns to the list only if it isn't already there. You could make a proc for that; 
my_randoms(min,max,num) //this proc takes 3 arguments: first like rand()'s arguments + how many numbers you want.
   var/list/numbers = new //initialize a new list
   while(numbers.len < num) //loop until our list has enough numbers in it
      var/N = rand(min,max) //generate a random number
      if(!(N in numbers)) //if the number isn't already in the numbers list
         numbers += N //add it (also increasing the length of the list in the process)
   return numbers //return the list to the proc caller
May 17 2008, 7:43 pm
In response to Kaioken
And yours has an indeterminate amount of overhead. It could be done in num iterations, it could be done in a million iterations, and it could never finish (if num > max-min). "Guess and check" is always the wrong choice.