A Tour of Go - [Exercise: Equivalent Binary Trees](https://tour.golang.org/concurrency/7) & [연습: 동등한 이진 트리](https://go-tour-kr.appspot.com/#70)

walker.go

package main

import "code.google.com/p/go-tour/tree"
import "fmt"

type Tree struct {
	Left  *Tree
	Value int
	Right *Tree
}

// Walk walks the tree t sending all values
// from the tree to the channel ch.
func Walk(t *tree.Tree, ch chan int) {
	if t == nil {
		return
	}
	// Inorder Traversal
	Walk(t.Left, ch)
	ch <- t.Value
	Walk(t.Right, ch)
}

func Walker(t *tree.Tree, ch chan int) {
	Walk(t, ch)
	close(ch)
}

// Same determines whether the trees
// t1 and t2 contain the same values.
func Same(t1, t2 *tree.Tree) bool {
	ch1 := make(chan int)
	ch2 := make(chan int)

	go Walker(t1, ch1)
	go Walker(t2, ch2)

	for x := range ch1 {
		if v := <-ch2; x != v {
			return false
		}
	}

	return true
}

func main() {
	fmt.Println(Same(tree.New(1), tree.New(1)))
	fmt.Println(Same(tree.New(2), tree.New(1)))
	fmt.Println(Same(tree.New(2), tree.New(2)))
}