Go Tour Exercise: Equivalent Binary Trees

Question

I am trying to solve equivalent binary trees exercise on go tour. Here is what I did;

package main

import \"tour/tree\"
import \"fmt\"

// Walk walks the tr         


        

Answer 1

You should avoid to let opened channels unattended or a thread can be waiting forever and never ending.

package main

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

func WalkRecurse(t *tree.Tree, ch chan int) {
    if t == nil {
        return
    }

    WalkRecurse(t.Left, ch)
    ch <- t.Value
    WalkRecurse(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) {
    WalkRecurse(t, ch)
    close(ch)
}

// Same determines whether the trees
// t1 and t2 contain the same values.
func Same(t1, t2 *tree.Tree) bool {
    var ch1, ch2 chan int = make(chan int), make(chan int)
    go Walk(t1, ch1)
    go Walk(t2, ch2)

    ret := true
    for {
        v1, ok1 := <- ch1
        v2, ok2 := <- ch2

        if ok1 != ok2 {
            ret = false
        }
        if ok1 && (v1 != v2) {
            ret = false
        }
        if !ok1 && !ok2 {
            break
        }
    }

    return ret
}

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

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