Data commit

Task/EKG-sequence-convergence/Go/ekg-sequence-convergence.go

@@ -0,0 +1,72 @@
+package main
+
+import (
+    "fmt"
+    "sort"
+)
+
+func contains(a []int, b int) bool {
+    for _, j := range a {
+        if j == b {
+            return true
+        }
+    }
+    return false
+}
+
+func gcd(a, b int) int {
+    for a != b {
+        if a > b {
+            a -= b
+        } else {
+            b -= a
+        }
+    }
+    return a
+}
+
+func areSame(s, t []int) bool {
+    le := len(s)
+    if le != len(t) {
+        return false
+    }
+    sort.Ints(s)
+    sort.Ints(t)
+    for i := 0; i < le; i++ {
+        if s[i] != t[i] {
+            return false
+        }
+    }
+    return true
+}
+
+func main() {
+    const limit = 100
+    starts := [5]int{2, 5, 7, 9, 10}
+    var ekg [5][limit]int
+
+    for s, start := range starts {
+        ekg[s][0] = 1
+        ekg[s][1] = start
+        for n := 2; n < limit; n++ {
+            for i := 2; ; i++ {
+                // a potential sequence member cannot already have been used
+                // and must have a factor in common with previous member
+                if !contains(ekg[s][:n], i) && gcd(ekg[s][n-1], i) > 1 {
+                    ekg[s][n] = i
+                    break
+                }
+            }
+        }
+        fmt.Printf("EKG(%2d): %v\n", start, ekg[s][:30])
+    }
+
+    // now compare EKG5 and EKG7 for convergence
+    for i := 2; i < limit; i++ {
+        if ekg[1][i] == ekg[2][i] && areSame(ekg[1][:i], ekg[2][:i]) {
+            fmt.Println("\nEKG(5) and EKG(7) converge at term", i+1)
+            return
+        }
+    }
+    fmt.Println("\nEKG5(5) and EKG(7) do not converge within", limit, "terms")
+}