(A Tour of Go #70) Exercise: Equivalent Binary Trees http://tour.golang.org/#70

binary_tree.go

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) {
    defer close(ch)
    var walk func(t *tree.Tree)
    walk = func(t *tree.Tree) {
        if t == nil { return }
        walk(t.Left)
        ch <- t.Value
        walk(t.Right)
    }
    walk(t)
}

// 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)
    for {
        i1, ok1 := <- ch1
        i2, ok2 := <- ch2
        if i1 != i2 || ok1 != ok2 { return false }
        if !ok1 || !ok2 { break }
    }
    return true
}

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