Doubly linked list
There are two lists with node structure
type Dnode struct {
data interface{}
prev *Dnode
next *Dnode
}
type DList struct {
head *Dnode
tail *Dnode
size int
}
Features:
1, except for the head and tail nodes 2, through any other nodes prev / next node point to pre- and post-
2, the pre-head node is the node empty, the node Similarly the tail node is empty post
The main API implemented as follows:
1, the query
Query list length
Query any node
2, add
Insert Node from the beginning
Node is inserted from the rear
Node is inserted from an arbitrary position
3, delete
Delete any node
4. Other
Print the list
Initialization list
Specific achieve the following:
package main
import "fmt"
type Dnode struct {
data interface{}
prev *Dnode
next *Dnode
}
type DList struct {
head *Dnode
tail *Dnode
size int
}
// Get the list length
func (dl *DList)getSize()int{
return dl.size
}
// Get the list head
func (dl *DList)getHead() *Dnode{
return dl.head
}
// Get the list tail
func (dl *DList)getTail() *Dnode{
return dl.tail
}
// initialization list
initDList function () (dl * DList) {
return &DList{
head:nil,
tail:nil,
size:0,
}
}
// Print the list
func (dl *DList) display(){
fmt.Println("DoubleLinkedList size is ",dl.size)
if dl.getSize() == 0{
return
}
ptr := dl.head
for ptr != nil{
fmt.Println("data is ",ptr.data)
ptr = ptr.next
}
}
// additional nodes in the head
func (dl *DList) addHeadNode(node *Dnode){
if dl.getSize() == 0{
dl.head = node
dl.tail = node
node.prev = nil
node.next = nil
}else{
dl.head.prev = node
node.prev = nil
node.next = dl.head
dl.head = node
}
dl.size += 1
}
// additional node in the tail
func (dl *DList) append(node *Dnode){
if dl.getSize() == 0 {
dl.head = node
dl.tail = node
node.prev = nil
node.next = nil
}else{
dl.tail.next = node
node.prev = dl.tail
node.next = nil
dl.tail = node
}
dl.size += 1
}
// add any node
func (dl *DList) insert(node *Dnode,index int){
if dl.getSize() == 0 {
dl.addHeadNode(node)
}
// Get the current value of the index for the index node
oldNode := dl.getNode(index)
node.next = oldNode
node.prev = oldNode.prev
oldNode.prev.next = node
oldNode.prev = node
dl.size ++
}
// query node
func (dl *DList) getNode(index int)(dnode *Dnode){
if dl.getSize() == 0 || index > dl.getSize() {
return nil
}
if index == 0{
return dl.head
}
node := dl.head
for i:=0;i<=index;i++{
dnode = node.next
}
return
}
// delete any node
func (dl *DList) remove(node *Dnode) {
// delete the default node tail
if node == nil || node == dl.tail{
node = dl.tail
dl.tail = node.prev
dl.tail.next = nil
}else if node == dl.head{
dl.head = node.next
dl.head.prev = nil
}else{
node.prev.next = node.next
node.next.prev = node.prev
}
dl.size --
}
func main() {
dl := initDList()
fmt.Println ( "add nodes from the beginning")
for i:=0;i<5;i++{
dnode: = {Dnode
data:i,
}
dl.addHeadNode(&dnode)
}
dl.display()
fmt.Println ( "add nodes from the end")
for i:=5;i<10;i++{
dnode: = {Dnode
data:i,
}
dl.append(&dnode)
}
dl.display()
fmt.Println ( "remove the last node")
dl.remove(nil)
dl.display()
fmt.Println ( "delete the first three node")
node := dl.getNode(3)
dl.remove(node)
dl.display()
fmt.Println ( "add a second node")
node = &Dnode{
data:3,
}
dl.insert(node,1)
dl.display()
}