Small exercise comparing binary trees from A Tour of Go

eq-binary-tree.go

// Exercise page can be found at
// https://tour.golang.org/concurrency/8
package main

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

/*
type Tree struct {
    Left  *Tree
    Value int
    Right *Tree
}
*/

func WalkRecur(t *tree.Tree, ch chan int) {
	if t == nil {
		return
	}
	if t.Left != nil {
		WalkRecur(t.Left, ch)
	}
	ch <- t.Value
	if t.Right != nil {
		WalkRecur(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) {
	WalkRecur(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)
	ch2 := make(chan int)
	
	go Walk(t1, ch1)
	go Walk(t2, ch2)
	
	i, ok1 := <-ch1
	j, ok2 := <-ch2
	
	for {
		if !ok1 && !ok2 {
			break
		}
		if !ok1 || ! ok2 {
			return false
		}
		if i != j {
			return false
		}
		i, ok1 = <-ch1
		j, ok2 = <-ch2
	}
	return true
}

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