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.

In reply to Re^3: How to not print the same random number by ysth
in thread How to not print the same random number by Anonymous Monk

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