(学习java)双向循环链表

//10-17双向循环链表public class DLineListNode {public static void main(String[] args) {DLineList L = new DLineList();L.addDNode(1);//L.addDNode(3);//L.addDNode(1, 2);L.deleteNode(1);L.list();}// 定义接口public interface List {public void list();public void addDNode(int data);public void addDNode(int i, int data);public void deleteNode(int i);}// 定义结点public static class DNode {private int data;private DNode prior;private DNode next;public DNode() {this.data = 0;this.prior = null;this.next = null;}public DNode(int data) {this.data = data;this.prior = null;this.next = null;}}public static class DLineList implements List {// 定义头结点private DNode head;// 定义链表长度private int size;// 构造函数 建立空链表public DLineList() {head = null;this.size = 0;}@Override// 链表的添加(尾插法)public void addDNode(int data) {if (head == null) {DNode node = new DNode(data);head = node;head.next = head.prior = head;size++;} else if (head.next == head) {DNode node = new DNode(data);node.next = head.next;node.prior = head;head.next = node;head.prior = node;size++;} else {DNode temp = head;while (temp.next != head) {temp = temp.next;}DNode node = new DNode(data);node.next = temp.next;temp.next.prior = node;node.prior = temp;temp.next = node;size++;}}@Override// 链表的指定位置插入public void addDNode(int i, int data) {if (i < 1 || i > size + 1) {System.out.println("插入的位置i不正确");} else if (i == 1) {DNode node = new DNode(data);node.next = head;node.prior = head.prior;head.prior.next = node;head.prior = node;head = node;size++;} else {DNode temp = head;for (int j = 2; j < i; j++) {temp = temp.next;}DNode node = new DNode(data);node.next = temp.next;node.prior = temp;temp.next.prior = node;temp.next = node;size++;}}@Override// 链表的遍历public void list() {if (head == null) {System.out.println("空链表");System.out.println("链表的长度" + size);} else {DNode temp = head;while (temp.next != head) {System.out.print(temp.data + "->");temp = temp.next;}System.out.println(temp.data);System.out.println("链表的长度" + size);}}@Override//结点的删除public void deleteNode(int i) {if(i<1 || i>size){System.out.println("错误的输出位置!");}else if(i == 1){head.next.prior = head.prior;head.prior.next = head.next;head = head.next;size--;if(head.next == head){head = null;}}else{DNode temp = head;if(i/2<size){for(int j=1;j<i;j++){temp = temp.next;}temp.next.prior = temp.prior;temp.prior.next = temp.next;temp = null;size--;}else{for(int j=0;j<size-i+1;j++){temp = temp.prior;}temp.next.prior = temp.prior;temp.prior.next = temp.next;temp = null;size--;}}}}}