A Tour of Go exercises (tour.golang.org)

Solutions

Ex 70: Equivalent Binary Trees
*****************************************
package main

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

// Walk walks the tree t sending all values
// from the tree to the channel ch.
func Walk(t *tree.Tree, ch chan int){
    //Following tour linearly, so recursive walk instead of using a queue
    if t == nil{
      return
    }
    
    //In order walks will allow us to check most easily
    Walk(t.Left, ch)
    ch <- t.Value
    Walk(t.Right, 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 func(){
      /*Since our walk is recursive (Queueless solution and the trees
      don't have pointers to parents) we make an anonymous
  		go function that closes the channel when all is done. 
  		This prevents goroutine deadlock*/
          
    	Walk(t1, ch1)
      close(ch1)
    }()
    go func(){
        Walk(t2, ch2)
        close(ch2)
    }()
    for{
        v1, ok1 := <- ch1
        v2, ok2 := <- ch2
        if ok1 != ok2 {
        	return false
        }
        if v1 != v2{
         return false   
        }
        if ok1 == false && ok2 == false{
         	return true   
        }
    }
}
func main() {
    fmt.Println(Same(tree.New(1), tree.New(1)))
}