Programming Forums - View Single Post - [vb6] need advice concerning a largescale non-recurring random number generator

chepfaust · Jun 7th, 2006, 5:56 PM

well, here's what i ended up doing.

i ended up having to limit the total number of generated numbers to 899, but i came up with (what i think is) a rather efficient way of generating 899 pseudo-random non-recurring numbers.

first i generate a list of three-digit sequential numbers. (i started with 100 because i didn't feel like messing with the number formatting to create values like 001. the fact that i started with 100 is also the reason i can only generate 899 numbers, instead of 999.)

(Toggle Plain Text)

100.txt
101.txt
...
349.txt
...
666.txt

then i add a certain number of random digits to the front of the sequential numbers. since everything in the sequential number list is already a unique value, it doesn't matter if i make duplicate numbers with my random number routine.

my output ends up looking like

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456100.txt
642101.txt
...
265349.txt
...
478666.txt

and i can have values like

(Toggle Plain Text)

884201.txt
884202.txt

without breaking anything.

if coded correctly, both of these operations can be performed within the same loop, thus eliminating the need to waste time comparing every single value to every single other value in the array.

i'm sure this can be implemented on a larger scale like i envisioned, but it is beyond my capabilities to pull that off.

Jun 7th, 2006, 5:56 PM	#6
chepfaust Programmer Join Date: Feb 2005 Posts: 62 Rep Power: 4	solution? well, here's what i ended up doing. i ended up having to limit the total number of generated numbers to 899, but i came up with (what i think is) a rather efficient way of generating 899 pseudo-random non-recurring numbers. first i generate a list of three-digit sequential numbers. (i started with 100 because i didn't feel like messing with the number formatting to create values like 001. the fact that i started with 100 is also the reason i can only generate 899 numbers, instead of 999.) (Toggle Plain Text) 100.txt 101.txt ... 349.txt ... 666.txt 100.txt 101.txt ... 349.txt ... 666.txt then i add a certain number of random digits to the front of the sequential numbers. since everything in the sequential number list is already a unique value, it doesn't matter if i make duplicate numbers with my random number routine. my output ends up looking like (Toggle Plain Text) 456100.txt 642101.txt ... 265349.txt ... 478666.txt 456100.txt 642101.txt ... 265349.txt ... 478666.txt and i can have values like (Toggle Plain Text) 884201.txt 884202.txt 884201.txt 884202.txt without breaking anything. if coded correctly, both of these operations can be performed within the same loop, thus eliminating the need to waste time comparing every single value to every single other value in the array. i'm sure this can be implemented on a larger scale like i envisioned, but it is beyond my capabilities to pull that off.