Data commit

Task/Pseudo-random-numbers-PCG32/Go/pseudo-random-numbers-pcg32.go

@@ -0,0 +1,51 @@
+package main
+
+import (
+    "fmt"
+    "math"
+)
+
+const CONST = 6364136223846793005
+
+type Pcg32 struct{ state, inc uint64 }
+
+func Pcg32New() *Pcg32 { return &Pcg32{0x853c49e6748fea9b, 0xda3e39cb94b95bdb} }
+
+func (pcg *Pcg32) seed(seedState, seedSequence uint64) {
+    pcg.state = 0
+    pcg.inc = (seedSequence << 1) | 1
+    pcg.nextInt()
+    pcg.state = pcg.state + seedState
+    pcg.nextInt()
+}
+
+func (pcg *Pcg32) nextInt() uint32 {
+    old := pcg.state
+    pcg.state = old*CONST + pcg.inc
+    pcgshifted := uint32(((old >> 18) ^ old) >> 27)
+    rot := uint32(old >> 59)
+    return (pcgshifted >> rot) | (pcgshifted << ((-rot) & 31))
+}
+
+func (pcg *Pcg32) nextFloat() float64 {
+    return float64(pcg.nextInt()) / (1 << 32)
+}
+
+func main() {
+    randomGen := Pcg32New()
+    randomGen.seed(42, 54)
+    for i := 0; i < 5; i++ {
+        fmt.Println(randomGen.nextInt())
+    }
+
+    var counts [5]int
+    randomGen.seed(987654321, 1)
+    for i := 0; i < 1e5; i++ {
+        j := int(math.Floor(randomGen.nextFloat() * 5))
+        counts[j]++
+    }
+    fmt.Println("\nThe counts for 100,000 repetitions are:")
+    for i := 0; i < 5; i++ {
+        fmt.Printf("  %d : %d\n", i, counts[i])
+    }
+}