Random number generator - 2

[merlinv]

I would like to use a better random number generator in dealing bridge hands. When I use rand , I don't get uniform selection. It tends to use some numbers more than others.

For example - I would like a number returned between 1-52.

The max_rand is about 32000+. The number returned is between 0-max_rand. If you mod it with 52 it is not uniform.

Any suggestions?

Thanks.

Merlinv

 

[Salem]

http://www.eskimo.com/~scs/C-faq/q13.16.html

Personally, I'd start with say

Card deck[52];

Then call rand() many times over to exchange

swap( deck[i], deck[j] );

This is called shuffling (like you do with a real deck)

Then you deal the cards in 0, 1, 2, 3, ... order without lots of tedious problems like trying to extract the last few cards because it takes too long for rand() to come up with a number you haven't guessed before.

--

 

[uolj]

I would do as Salem suggests, but use random_shuffle from <algorithm> to shuffle the "cards" in the array or vector. The shuffling code has already been written for you. Note that you still must seed with srand() for random_shuffle to be different for each program run.