go語言Exercise: Equivalent Binary Trees

1. Implement the Walk function.

2. Test the Walk function.

The function tree.New(k) constructs a randomly-structured binary tree holding the values k, 2k, 3k, ..., 10k.

Create a new channel ch and kick off the walker:

go Walk(tree.New(1), ch)

Then read and print 10 values from the channel. It should be the numbers 1, 2, 3, ..., 10.

3. Implement the Same function using Walk to determine whether t1and t2 store the same values.

4. Test the Same function.

Same(tree.New(1), tree.New(1)) should return true, andSame(tree.New(1), tree.New(2)) should return false.

package main

import (
"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.Left != nil {
Walk(t.Left, ch)
}
ch <- t.Value
if t.Right != nil {
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 Walk(t1, ch1)
go Walk(t2, ch2)
for i := 0; i < 10; i++ {
if <-ch1 != <-ch2 {
return false
}
}
return true
}

func main() {
ch := make(chan int)
go Walk(tree.New(1), ch)

for i := 0; i < 10; i++ {
fmt.Println(<-ch)
}

fmt.Println("Equivalent Binary Trees?",Same(tree.New(1), tree.New(1)))
fmt.Println("Equivalent Binary Trees?",Same(tree.New(1), tree.New(2)))
}