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@kaipakartik
Created December 25, 2013 07:00
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Exercise: Equivalent Binary Trees
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) {
WalkRecursive(t, ch)
close(ch)
}
func WalkRecursive(t *tree.Tree, ch chan int) {
if t != nil {
WalkRecursive(t.Left, ch)
ch <- t.Value
WalkRecursive(t.Right, ch)
}
}
// Same determines whether the trees
// t1 and t2 contain the same values.
func Same(t1, t2 *tree.Tree) bool {
ch1, ch2 := make(chan int), make(chan int)
go Walk(t1, ch1)
go Walk(t2, ch2)
for {
n1, ok1 := <- ch1
n2, ok2 := <- ch2
if ok1 != ok2 || n1 != n2 {
return false
}
if !ok1 {
break;
}
}
return true
}
func main() {
ch := make(chan int)
go Walk(tree.New(1), ch)
fmt.Println(Same(tree.New(1), tree.New(2)))
fmt.Println(Same(tree.New(1), tree.New(1)))
fmt.Println(Same(tree.New(2), tree.New(1)))
}
@xian-wen
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package main

import (
	"golang.org/x/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) {
	walkR(t, ch)
	close(ch)
}

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

	walkR(t.Left, ch)
	ch <- t.Value
	walkR(t.Right, ch)
}

func readChan(ch chan int) string {
	l := []int{}
	for v := range ch {
		l = append(l, v)
	}
	return fmt.Sprint(l)
}

// Same determines whether the trees
// t1 and t2 contain the same values.
func Same(t1, t2 *tree.Tree) bool {
	ch1, ch2 := make(chan int), make(chan int)
	go Walk(t1, ch1)
	go Walk(t2, ch2)
	s1, s2 := readChan(ch1), readChan(ch2)
	return s1 == s2
}

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

@curbol
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curbol commented Jun 13, 2023

package main

import (
	"fmt"

	"golang.org/x/tour/tree"
)

// 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 == nil {
		close(ch)
		return
	}

	stack, cur := []*tree.Tree{}, t
	for cur != nil || len(stack) > 0 {
		for cur != nil {
			stack = append(stack, cur)
			cur = cur.Left
		}
		cur = stack[len(stack)-1]
		stack = stack[:len(stack)-1]
		ch <- cur.Value
		cur = cur.Right
	}
	close(ch)
}

type counts struct {
	v1 int
	v2 int
}

// Same determines whether the trees
// t1 and t2 contain the same values.
func Same(t1, t2 *tree.Tree) bool {
	ch1, ch2 := make(chan int, 10), make(chan int, 10)
	go Walk(t1, ch1)
	go Walk(t2, ch2)

	values := map[int]counts{}
	for n := 2; n > 0; {
		select {
		case v, ok := <-ch1:
			if !ok {
				n, ch1 = n-1, nil
			}
			c, ok := values[v]
			if !ok {
				values[v] = counts{1, 0}
			} else {
				c.v1++
				values[v] = c
			}
		case v, ok := <-ch2:
			if !ok {
				n, ch2 = n-1, nil
			}
			c, ok := values[v]
			if !ok {
				values[v] = counts{0, 1}
			} else {
				c.v2++
				values[v] = c
			}
		}
	}

	for _, c := range values {
		if c.v1 != c.v2 {
			return false
		}
	}
	return true
}

func main() {
	ch := make(chan int, 10)
	go Walk(tree.New(1), ch)
	for v := range ch {
		fmt.Println(v)
	}

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

@vvvitaly
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vvvitaly commented Jan 26, 2024

package main

import (
	"golang.org/x/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)
	}
	
	if t.Right != nil {
		Walk(t.Right, ch)
	}
	
	ch <- t.Value
}

// Same determines whether the trees
// t1 and t2 contain the same values.
func Same(t1, t2 *tree.Tree) bool {
	ch := make(chan int, 20)
	go Walk(t1, ch)
	go Walk(t2, ch)
		
	res := 0
	for i := 0; i < 20; i++ {
		val := <-ch
		res ^= val
	}
	
	return res == 0
}

func main() {
	t1, t2 := tree.New(1), tree.New(1)
	fmt.Printf("%v\n%v\n%v\n*****\n", t1, t2, Same(t1, t2))	
	
	t1, t2 = tree.New(2), tree.New(3)
	fmt.Printf("%v\n%v\n%v\n*****\n", t1, t2, Same(t1, t2))	
}

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