链表的基本操作

package com.zyf.data;import java.util.Hashtable;import org.junit.Test;/** *链表的基本操作  * @author zyf * */public class MyLinkedList{Node head = null;//链表头引用public void addNode(int d){Node newNode = new Node(d);if(head == null){head = newNode;return;}Node tmp = head;while(tmp.next != null){tmp = tmp.next;}//add node to endtmp.next = newNode;}/** * @param index:删除第index个结点 * @return 成功返回true， 失败返回false */public Boolean deleteNode(int index){if(index <1 || index > length()){return false;}//删除链表第一个元素if(index == 1){head = head.next;return true;}int i = 1;Node preNode = head;Node curNode = preNode.next;while(curNode != null){if(i == index){preNode.next = curNode.next;return true;}preNode = curNode;curNode = curNode.next;i++;}return true;}/** * @return 返回结点的长度 */public int length(){int length = 0;Node tmp = head;while(tmp != null){length ++;tmp = tmp.next;}return length;}/** * 对链表进行排序 * 返回排序后的头结点 */public Node orderList(){Node nextNode = null;int temp = 0;Node curNode = head;while(curNode.next != null){nextNode = curNode.next;while(nextNode != null){if(curNode.data > nextNode.data){temp = curNode.data;curNode.data = nextNode.data;nextNode.data = temp;}nextNode = nextNode.next;}curNode = curNode.next;}return head;}public void printList(){Node tmp = head;while(tmp != null){System.out.println(tmp.data);tmp = tmp.next;}}@Testpublic static void main(String[] args){MyLinkedList list = new MyLinkedList();list.addNode(5);list.addNode(3);list.addNode(1);list.addNode(3);System.out.println("listLen = " + list.length());System.out.println("before order:");list.printList();list.orderList();System.out.println("after order:");list.printList();//findElem(1,2);}//从链表中删除重复的数据public void deleteDuplecate(Node head){Hashtable<Integer,Integer> table = new Hashtable<Integer,Integer>();Node tmp = head;Node pre = null;while(tmp!=null){if(table.containsKey(tmp.data))pre.next = tmp.next;else{table.put(tmp.data, 1);pre=tmp;}tmp = tmp.next;}}public void deleteDuplecate_1(Node head){Node p = head;while(p != null){Node q = p;while(q.next != null){if(p.data == q.next.data){q.next = q.next.next;}elseq = q.next;}p = p.next;}}//如何找出单链表中的倒数第k个元素@Testpublic Node findElem(Node head,int k){if(k<1 || k >this.length())return null;Node p1 = head;Node p2 = head;for(int i =0 ;i < k-1;i++)p1 = p1.next;while(p1 != null){p1 = p1.next;p2 = p2.next;}return p2;}//如何实现链表的反转public void ReverseIteratively(Node head){Node pReversedHead = head;Node pNode = head;Node pPrev = null;while(pNode != null){Node pNext = pNode.next;if(pNext == null)pReversedHead = pNode;pNode.next = pPrev;pPrev = pNode;pNode = pNext;}this.head = pReversedHead;}//如何从尾到头输出单链表public void printListReversely(Node pListHead){if(pListHead != null){printListReversely(pListHead.next);System.out.println(pListHead.data);}}//如何寻找单链表的中间结点public Node SearchMid(Node head){Node p = this.head;Node q = this.head;while(p != null && p.next != null && p.next.next != null){p = p.next.next;q = q.next;}return q;}//如何检测一个链表是否有环 public boolean IsLoop(Node head){ Node fast = head; Node slow = head; if(fast == null){ return false; } while(fast!=null && fast.next != null){ fast = fast.next.next; slow = slow.next; if(fast == slow){ return true; } } return !(fast == null || fast.next == null); } public Node FindLoopPort(Node head){ Node slow = head,fast = head; while(fast != null && fast.next != null){ slow = slow.next; fast = fast.next.next; if(slow == fast) break; } if(fast == null || fast.next == null) return null; slow = head; while(slow != fast){ slow = slow.next; fast = fast.next; } return slow; } //如何在不知道头指针的情况下删除指定结点 public boolean deleteNode(Node n){ if(n == null || n.next == null) return false; int tmp = n.data; n.data = n.next.data; n.next.data = tmp; n.next = n.next.next; return true; } //如何判断两个链表是否相交 public boolean isIntersect(Node h1,Node h2){ if(h1 == null || h2 == null) return false; Node tail1 = h1; while(tail1.next != null) tail1 = tail1.next; Node tail2 = h2; while(tail2.next != null){ tail2 = tail2.next; } return tail1 == tail2; }  public static Node getFirstMeetNode(Node h1,Node h2){ if(h1 == null || h2 == null) return null; Node tail = h1; int len1 = 1; //找到链表h1的最后一个结点 while(tail.next != null){ tail = tail.next; len1 ++; } Node tail2 = h2; int len2 = 1; while(tail2.next != null){ tail2 = tail2.next; len2 ++; }  if(tail != tail2){ return null; } Node t1 = h1; Node t2 = h2; //找出较长的链表，先遍历 if(len1 > len2){ int d = len1 = len2; while(d != 0){ t1 = t1.next; d--; } } else{ int d = len2 - len1; while(d != 0){ t2 = t2.next; d--; } } while(t1 != t2){ t1 = t1.next; t2 = t2.next; } return t1; } //.}