Initial data commit

Task/Non-continuous-subsequences/Go/non-continuous-subsequences.go

@@ -0,0 +1,39 @@
+package main
+
+import "fmt"
+
+const ( // state:
+    m   = iota // missing:  all elements missing so far
+    c          // continuous:  all elements included so far are continuous
+    cm         // one or more continuous followed by one or more missing
+    cmc        // non-continuous subsequence
+)
+
+func ncs(s []int) [][]int {
+    if len(s) < 3 {
+        return nil
+    }
+    return append(n2(nil, s[1:], m), n2([]int{s[0]}, s[1:], c)...)
+}
+
+var skip = []int{m, cm, cm, cmc}
+var incl = []int{c, c, cmc, cmc}
+
+func n2(ss, tail []int, seq int) [][]int {
+    if len(tail) == 0 {
+        if seq != cmc {
+            return nil
+        }
+        return [][]int{ss}
+    }
+    return append(n2(append([]int{}, ss...), tail[1:], skip[seq]),
+        n2(append(ss, tail[0]), tail[1:], incl[seq])...)
+}
+
+func main() {
+    ss := ncs([]int{1, 2, 3, 4})
+    fmt.Println(len(ss), "non-continuous subsequences:")
+    for _, s := range ss {
+        fmt.Println("  ", s)
+    }
+}