代碼如下
package main
import (
"fmt"
)
type Node struct {
Value string
Left, Right *Node
}
func (node *Node) Print() {
fmt.Print(node.Value, " ")
}
func (node *Node) SetValue(v string) {
if node == nil {
fmt.Println("setting value to nil.node ignored.")
return
}
node.Value = v
}
//前序遍歷
func (node *Node) PreOrder() {
if node == nil {
return
}
node.Print()
node.Left.PreOrder()
node.Right.PreOrder()
}
//中序遍歷
func (node *Node) MiddleOrder() {
if node == nil {
return
}
node.Left.MiddleOrder()
node.Print()
node.Right.MiddleOrder()
}
//後序遍歷
func (node *Node) PostOrder() {
if node == nil {
return
}
node.Left.PostOrder()
node.Right.PostOrder()
node.Print()
}
//層次遍歷(廣度優先遍歷)
func (node *Node) BreadthFirstSearch() {
if node == nil {
return
}
result := []string{}
nodes := []*Node{node}
for len(nodes) > 0 {
curNode := nodes[0]
nodes = nodes[1:]
result = append(result, curNode.Value)
if curNode.Left != nil {
nodes = append(nodes, curNode.Left)
}
if curNode.Right != nil {
nodes = append(nodes, curNode.Right)
}
}
for _, v := range result {
fmt.Print(v, " ")
}
}
//層數(遞歸實現)
//對任意一個子樹的根節點來說，它的深度=左右子樹深度的最大值+1
func (node *Node) Layers() int {
if node == nil {
return 0
}
leftLayers := node.Left.Layers()
rightLayers := node.Right.Layers()
if leftLayers > rightLayers {
return leftLayers + 1
} else {
return rightLayers + 1
}
}
//層數(非遞歸實現)
//藉助隊列，在進行按層遍歷時，記錄遍歷的層數即可
func (node *Node) LayersByQueue() int {
if node == nil {
return 0
}
layers := 0
nodes := []*Node{node}
for len(nodes) > 0 {
layers++
size := len(nodes) //每層的節點數
count := 0
for count < size {
count++
curNode := nodes[0]
nodes = nodes[1:]
if curNode.Left != nil {
nodes = append(nodes, curNode.Left)
}
if curNode.Right != nil {
nodes = append(nodes, curNode.Right)
}
}
}
return layers
}
func CreateNode(v string) *Node {
return &Node{Value: v}
}
func main() {
root := Node{Value: "A"}
root.Left = &Node{}
root.Left.SetValue("B")
root.Left.Right = CreateNode("C")
root.Right = &Node{"D", nil, nil}
root.Right.Left = CreateNode("E")
fmt.Print("\n前序遍歷: ")
root.PreOrder()
fmt.Print("\n中序遍歷: ")
root.MiddleOrder()
fmt.Print("\n後序遍歷: ")
root.PostOrder()
fmt.Print("\n層次遍歷: ")
root.BreadthFirstSearch()
fmt.Println("\n層數: ", root.Layers())
fmt.Println("\n層數: ", root.LayersByQueue())}
```
**結果如下：**
