Created
March 4, 2019 06:28
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An Answer to A Tour of Go Exercise: Equivalent Binary Trees
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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) { | |
if t != nil { // if empty node, stop looking | |
Walk(t.Left, ch) // otherwise, look left first | |
ch <- t.Value // send the current node to the channel | |
Walk(t.Right, ch) // and look right | |
} // continue until all looks come up empty | |
} | |
// 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) // make channels | |
go func() { // go to the first tree | |
Walk(t1, ch1) // kick off the walker | |
close(ch1) // wait to close until the walk is done | |
}() // call the go | |
go func() { // repeat for the second tree | |
Walk(t2, ch2) | |
close(ch2) | |
}() | |
for i := range ch1 { // iterate over one of the channels | |
if i != <-ch2 { // at each step, see if nodes are the same | |
return false // if not, trees are not the same | |
} | |
} | |
return true // if no dissimilar nodes, trees are the same | |
} | |
func main() { | |
ch := make(chan int) | |
go func() { // test walk a tree | |
Walk(tree.New(1), ch) | |
close(ch) // make sure to close when walk is done | |
}() | |
for i := range ch { | |
fmt.Println(i) | |
} | |
fmt.Println(Same(tree.New(1), tree.New(1))) // should be true | |
fmt.Println(Same(tree.New(1), tree.New(2))) // should be false | |
} |
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