gistfile1.go

package main

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

// 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
	}
	Walk(t.Left, ch)
	ch <- t.Value
	Walk(t.Right, 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)
	closeWalk := func(t *tree.Tree, ch chan int) {
		Walk(t, ch)
		close(ch)
	}

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

	for {
		v1, ok1 := <-ch1
		v2, ok2 := <-ch2
		if v1 != v2 || ok1 != ok2 {
			return false
		}
		if !ok1 {
			break
		}
	}
	return true
}

func main() {
	fmt.Println(Same(tree.New(2), tree.New(4)))
}