Data commit

Task/Yellowstone-sequence/Go/yellowstone-sequence.go

@@ -0,0 +1,64 @@
+package main
+
+import (
+    "fmt"
+    "log"
+    "os/exec"
+)
+
+func gcd(x, y int) int {
+    for y != 0 {
+        x, y = y, x%y
+    }
+    return x
+}
+
+func yellowstone(n int) []int {
+    m := make(map[int]bool)
+    a := make([]int, n+1)
+    for i := 1; i < 4; i++ {
+        a[i] = i
+        m[i] = true
+    }
+    min := 4
+    for c := 4; c <= n; c++ {
+        for i := min; ; i++ {
+            if !m[i] && gcd(a[c-1], i) == 1 && gcd(a[c-2], i) > 1 {
+                a[c] = i
+                m[i] = true
+                if i == min {
+                    min++
+                }
+                break
+            }
+        }
+    }
+    return a[1:]
+}
+
+func check(err error) {
+    if err != nil {
+        log.Fatal(err)
+    }
+}
+
+func main() {
+    x := make([]int, 100)
+    for i := 0; i < 100; i++ {
+        x[i] = i + 1
+    }
+    y := yellowstone(100)
+    fmt.Println("The first 30 Yellowstone numbers are:")
+    fmt.Println(y[:30])
+    g := exec.Command("gnuplot", "-persist")
+    w, err := g.StdinPipe()
+    check(err)
+    check(g.Start())
+    fmt.Fprintln(w, "unset key; plot '-'")
+    for i, xi := range x {
+        fmt.Fprintf(w, "%d %d\n", xi, y[i])
+    }
+    fmt.Fprintln(w, "e")
+    w.Close()
+    g.Wait()
+}