Data commit

Task/Kolakoski-sequence/Go/kolakoski-sequence.go

@@ -0,0 +1,86 @@
+package main
+
+import "fmt"
+
+func nextInCycle(c []int, index int) int {
+    return c[index % len(c)]
+}
+
+func kolakoski(c []int, slen int) []int {
+    s := make([]int, slen)
+    i, k := 0, 0
+    for {
+        s[i] = nextInCycle(c, k)
+        if s[k] > 1 {
+            for j := 1; j < s[k]; j++ {
+                i++
+                if i == slen {
+                    return s
+                }
+                s[i] = s[i - 1]
+            }
+        }
+        i++
+        if i == slen {
+            return s
+        }
+        k++
+    }
+}
+
+func possibleKolakoski(s []int) bool {
+    slen := len(s)
+    rle := make([]int, 0, slen)
+    prev := s[0]
+    count := 1
+    for i := 1; i < slen; i++ {
+        if s[i] == prev {
+            count++
+        } else {
+            rle = append(rle, count)
+            count = 1
+            prev = s[i]
+        }
+    }
+    // no point adding final 'count' to rle as we're not going to compare it anyway
+    for i := 0; i < len(rle); i++ {
+        if rle[i] != s[i] {
+            return false
+        }
+    }
+    return true
+}
+
+func printInts(ia []int, suffix string) {
+    fmt.Print("[")
+    alen := len(ia)
+    for i := 0; i < alen; i++ {
+        fmt.Print(ia[i])
+        if i < alen - 1 {
+            fmt.Print(", ")
+        }
+    }
+    fmt.Printf("]%s\n", suffix)
+}
+
+func main() {
+    ias := make([][]int, 4)
+    ias[0] = []int{1, 2}
+    ias[1] = []int{2, 1}
+    ias[2] = []int{1, 3, 1, 2}
+    ias[3] = []int{1, 3, 2, 1}
+    slens := []int{20, 20, 30, 30}
+    for i, ia := range ias {
+        slen := slens[i]
+        kol := kolakoski(ia, slen)
+        fmt.Printf("First %d members of the sequence generated by ", slen)
+        printInts(ia, ":")
+        printInts(kol, "")
+        p := possibleKolakoski(kol)
+        poss := "Yes"
+        if !p {
+            poss = "No"
+        }
+        fmt.Println("Possible Kolakoski sequence?", poss, "\n")
+    }
+}