Another update from ingydotnet^djgoku

Task/Visualize-a-tree/Go/visualize-a-tree-3.go

@@ -0,0 +1,46 @@
+package main
+
+import "fmt"
+
+type tree []node
+
+type node struct {
+    label    string
+    children []int // indexes into tree
+}
+
+func main() {
+    vis(tree{
+        0: node{"root", []int{1, 2, 3}},
+        1: node{"ei", []int{4, 5}},
+        2: node{"bee", nil},
+        3: node{"si", nil},
+        4: node{"dee", nil},
+        5: node{"y", []int{6}},
+        6: node{"eff", nil},
+    })
+}
+
+func vis(t tree) {
+    if len(t) == 0 {
+        fmt.Println("<empty>")
+        return
+    }
+    var f func(int, string)
+    f = func(n int, pre string) {
+        ch := t[n].children
+        if len(ch) == 0 {
+            fmt.Println("╴", t[n].label)
+            return
+        }
+        fmt.Println("┐", t[n].label)
+        last := len(ch) - 1
+        for _, ch := range ch[:last] {
+            fmt.Print(pre, "├─")
+            f(ch, pre+"│ ")
+        }
+        fmt.Print(pre, "└─")
+        f(ch[last], pre+"  ")
+    }
+    f(0, "")
+}