package main

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

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

func WalkRecursive(t *tree.Tree, ch chan int) {
    if t != nil {
        WalkRecursive(t.Left, ch)
        ch <- t.Value
        WalkRecursive(t.Right, ch)
    }
}

// Same determines whether the trees
// t1 and t2 contain the same values.
func Same(t1, t2 *tree.Tree) bool {
    ch1, ch2 := make(chan int), make(chan int)
    go Walk(t1, ch1)
    go Walk(t2, ch2)
    for {
        n1, ok1 := <- ch1
        n2, ok2 := <- ch2
        if ok1 != ok2 || n1 != n2 {
        	return false
        }
        if !ok1 {
        	break;
        }
    }
    return true
    
    
}

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