Exercise: Equivalent Binary Trees

exercise-equivalent-binary-trees.go

package main

import (
	"golang.org/x/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) {
	if t != nil {
		Walk(t.Left, ch)
		ch <- t.Value
		Walk(t.Right, ch)
	}
}

func goWalk(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, 100)
	ch2 := make(chan int, 100)

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

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

		if (ok1 == false) {
			break;
		}
	}

	return true
}

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