move out c/cpp/py

cl/_testgo/tprecur/in.go

@@ -0,0 +1,36 @@
+package main
+
+func main() {
+	recursive()
+}
+
+func recursive() {
+	type T int
+	if got, want := recur1[T](5), T(110); got != want {
+		panic("error")
+	}
+}
+
+type Integer interface {
+	~int | ~int32 | ~int64
+}
+
+func recur1[T Integer](n T) T {
+	if n == 0 || n == 1 {
+		return T(1)
+	} else {
+		return n * recur2(n-1)
+	}
+}
+
+func recur2[T Integer](n T) T {
+	list := make([]T, n)
+	for i, _ := range list {
+		list[i] = T(i + 1)
+	}
+	var sum T
+	for _, elt := range list {
+		sum += elt
+	}
+	return sum + recur1(n-1)
+}