Exercise: Equivalent Binary Trees http://tour.golang.org/#70

slide70.go

package main

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

func main() {
	ch := make(chan int)
	go Walk(tree.New(1), ch)
	for v := range ch {
		fmt.Println(v)
	}
	fmt.Println(Same(tree.New(1), tree.New(1)))
	fmt.Println(Same(tree.New(1), tree.New(2)))
}

func Walk(t *tree.Tree, ch chan<- int) {
	var walker func(*tree.Tree)
	walker = func(t *tree.Tree) {
		for t != nil {
			walker(t.Left)
			ch <- t.Value
			t = t.Right
		}
	}
	walker(t)
	close(ch)
}

func Same(t1, t2 *tree.Tree) bool {
	ch1, ch2 := make(chan int), make(chan int)
	var v1, v2 int
	var ok bool

	go Walk(t1, ch1)
	go Walk(t2, ch2)
	for v1 = range ch1 {
		v2, ok = <-ch2
		if !ok || v1 != v2 {
			return false
		}
	}
	v2, ok = <-ch2
	return !ok
}