Solution to A Tour of Go - Exercise: Equivalent Binary Trees

trees.go

package main

import "golang.org/x/tour/tree"
import "fmt"
import "reflect"

// Walk walks the tree t sending all values
// from the tree to the channel ch.
func Walk(t *tree.Tree, ch chan int) {
  var walk func(t *tree.Tree)

  // Need this inner recursion to allow me to close the channel.
  walk = func(t *tree.Tree) {
    if t == nil {
      return
    }
    walk(t.Left)
    ch <- t.Value
    walk(t.Right)
  }
  walk(t)
  close(ch)
}

// Same determines whether the trees
// t1 and t2 contain the same values.
func Same(t1, t2 *tree.Tree) bool {
  ch, ch2 := make(chan int), make(chan int)
  go Walk(t1, ch)
  go Walk(t2, ch2)

  t1s, t2s := make([]int, 0), make([]int, 0)
  for i := range ch {
    t1s = append(t1s, i)
  }
  for i := range ch2 {
    t2s = append(t2s, i)
  }

  // Not the fastest way of comparing, very convenient though :)
  return reflect.DeepEqual(t1s, t2s)
}

func main() {
  fmt.Println("Should be true:", Same(tree.New(1), tree.New(1)))
  fmt.Println("Should be false:", Same(tree.New(1), tree.New(2)))
}