Go Tour: Equivalent Binary Trees

bintree_equivalence.go

package main

import (
	"golang.org/x/tour/tree"
	"fmt"
)


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

// Walk walks the tree t sending all values
// from the tree to the channel ch.
func Walk(t *tree.Tree, ch chan int){
	walkrec(t, ch)
	close(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 i := range ch1 {
	j, ok := <- ch2
		if !ok || i != j {
			return false
		}
	}
	return true
}

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)))
}