Data commit

Task/Knuths-power-tree/Go/knuths-power-tree.go

@@ -0,0 +1,68 @@
+package main
+
+import (
+    "fmt"
+    "math/big"
+)
+
+var (
+    p   = map[int]int{1: 0}
+    lvl = [][]int{[]int{1}}
+)
+
+func path(n int) []int {
+    if n == 0 {
+        return []int{}
+    }
+    for {
+        if _, ok := p[n]; ok {
+            break
+        }
+        var q []int
+        for _, x := range lvl[0] {
+            for _, y := range path(x) {
+                z := x + y
+                if _, ok := p[z]; ok {
+                    break
+                }
+                p[z] = x
+                q = append(q, z)
+            }
+        }
+        lvl[0] = q
+    }
+    r := path(p[n])
+    r = append(r, n)
+    return r
+}
+
+func treePow(x float64, n int) *big.Float {
+    r := map[int]*big.Float{0: big.NewFloat(1), 1: big.NewFloat(x)}
+    p := 0
+    for _, i := range path(n) {
+        temp := new(big.Float).SetPrec(320)
+        temp.Mul(r[i-p], r[p])
+        r[i] = temp
+        p = i
+    }
+    return r[n]
+}
+
+func showPow(x float64, n int, isIntegral bool) {
+    fmt.Printf("%d: %v\n", n, path(n))
+    f := "%f"
+    if isIntegral {
+        f = "%.0f"
+    }
+    fmt.Printf(f, x)
+    fmt.Printf(" ^ %d = ", n)
+    fmt.Printf(f+"\n\n", treePow(x, n))
+}
+
+func main() {
+    for n := 0; n <= 17; n++ {
+        showPow(2, n, true)
+    }
+    showPow(1.1, 81, false)
+    showPow(3, 191, true)
+}