Re^2: How to not print the same random number

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Re^3: How to not print the same random number by borisz (Canon) on Mar 04, 2006 at 11:05 UTC
Yes sure, the array with all numbers is build and shuffled. On the other hand, hash solutions require more memory and more cpu power they build the same array but slower. A hash is a better choice, if you use only some number out of a large range. For really really much numbers a database is my best choice. Boris	[reply]
Re^4: How to not print the same random number by shotgunefx (Parson) on Mar 04, 2006 at 11:08 UTC
That's what I figured. I haven't kept up lately, didn't know if some lazy evaluation had snuck in there ;) -Lee "To be civilized is to deny one's nature."	[reply]
Re^3: How to not print the same random number by ysth (Canon) on Mar 05, 2006 at 07:53 UTC
Not much of a hog. Storing the numbers already picked in a hash would be about as bad. (I'm not sure how many copies of the list the shuffle approach will end up having.) But anyway, if you go with what I understand to be your idea of repeatedly generating random numbers until you find one not yet in a hash, you'll end up taking a very very long time finding the last few numbers if the limit is, say, 1000000.	[reply]
Re^4: How to not print the same random number by shotgunefx (Parson) on Mar 05, 2006 at 20:43 UTC
Well, I suppose I should have been more clear. I would think for many applications, the number of numbers picked compared to the number range would be relatively small. So I guess the proper answer would be, "it depends". -Lee "To be civilized is to deny one's nature."	[reply]
Re^3: How to not print the same random number by fishbot_v2 (Chaplain) on Mar 04, 2006 at 15:30 UTC
The question becomes "are you going to use all the numbers in that range?" If so, you have to remember them all regardless of your approach. If no, then you could save memory by just tracking what you use... but this then becomes more processor-expensive.	[reply]
Re^4: How to not print the same random number by shotgunefx (Parson) on Mar 04, 2006 at 17:36 UTC
On the plus side, once you've "bought it", the cost is pretty much constant. -Lee "To be civilized is to deny one's nature."	[reply]


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