Data commit

Task/Hofstadter-Q-sequence/Go/hofstadter-q-sequence.go

@@ -0,0 +1,46 @@
+package main
+
+import "fmt"
+
+var m map[int]int
+
+func initMap() {
+    m = make(map[int]int)
+    m[1] = 1
+    m[2] = 1
+}
+
+func q(n int) (r int) {
+    if r = m[n]; r == 0 {
+        r = q(n-q(n-1)) + q(n-q(n-2))
+        m[n] = r
+    }
+    return
+}
+
+func main() {
+    initMap()
+    // task
+    for n := 1; n <= 10; n++ {
+        showQ(n)
+    }
+    // task
+    showQ(1000)
+    // extra credit
+    count, p := 0, 1
+    for n := 2; n <= 1e5; n++ {
+        qn := q(n)
+        if qn < p {
+            count++
+        }
+        p = qn
+    }
+    fmt.Println("count:", count)
+    // extra credit
+    initMap()
+    showQ(1e6)
+}
+
+func showQ(n int) {
+    fmt.Printf("Q(%d) = %d\n", n, q(n))
+}