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Pseudo-random numbers/Splitmix64: Difference between revisions
→{{header|Nim}}
Alextretyak (talk | contribs) m (→{{header|11l}}) |
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Line 422:
0: 20027 1: 19892 2: 20073 3: 19978 4: 20030
</pre>
=={{header|Nim}}==
<lang Nim>import math, sequtils, strutils
const Two64 = 2.0^64
type Splitmix64 = object
state: uint64
func initSplitmix64(seed: uint64): Splitmix64 =
## Initialize a Splitmiax64 PRNG.
Splitmix64(state: seed)
func nextInt(r: var Splitmix64): uint64 =
## Return the next pseudorandom integer (actually a uint64 value).
r.state += 0x9e3779b97f4a7c15u
var z = r.state
z = (z xor z shr 30) * 0xbf58476d1ce4e5b9u
z = (z xor z shr 27) * 0x94d049bb133111ebu
result = z xor z shr 31
func nextFloat(r: var Splitmix64): float =
## Retunr the next pseudorandom float (between 0.0 and 1.0 excluded).
r.nextInt().float / Two64
when isMainModule:
echo "Seed = 1234567:"
var prng = initSplitmix64(1234567)
for i in 1..5:
echo i, ": ", ($prng.nextInt).align(20)
echo "\nSeed = 987654321:"
var counts: array[0..4, int]
prng = initSplitmix64(987654321)
for _ in 1..100_000:
inc counts[int(prng.nextFloat * 5)]
echo toSeq(counts.pairs).mapIt(($it[0]) & ": " & ($it[1])).join(", "</lang>
{{out}}
<pre>Seed = 1234567:
1: 6457827717110365317
2: 3203168211198807973
3: 9817491932198370423
4: 4593380528125082431
5: 16408922859458223821
Seed = 987654321:
0: 20027, 1: 19892, 2: 20073, 3: 19978, 4: 20030</pre>
=={{header|Perl}}==
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