Java与算法（4）

Java与算法（4）

题目：

给定两个有序链表的头指针head1和head2，打印两个链表的公共部分

public class CommonPart {public static class Node {int data;Node next;public Node(int data) {this.data = data;}}public void printLink(Node head) {while (head!=null) {System.out.println(head.data+" ");head=head.next;}System.out.println();}public void getCommenPart(Node h1,Node h2) {while (h1!=null&&h2!=null) {if (h1.data>h2.data) {h2=h2.next;} else if(h1.data<h2.data) {h1 = h1.next;} else {System.out.println(h1.data);h1 = h1.next;h2 = h2.next;}}System.out.println("");}public static void main(String[] args) {Node node1 = new Node(1);node1.next = new Node(3);node1.next.next = new Node(7);node1.next.next.next = new Node(8);node1.next.next.next.next = new Node(9);Node node2 = new Node(2);node2.next = new Node(3);node2.next.next = new Node(9);node2.next.next.next = new Node(10);node2.next.next.next.next = new Node(11);CommonPart commonPart =  new CommonPart();commonPart.printLink(node1);commonPart.printLink(node2);commonPart.getCommenPart(node1, node2);}}

题目：

分别实现两个函数，一个可以删除单链表倒数第k个节点，另一个可以删除双链表倒数第k个节点。

public class DeleteLastSlink {public static class Node {int data;Node next;public Node(int data) {this.data = data;}}public Node deleteLast(Node head,int k) {if (head == null && k<1) {return head;}Node curnode = head;while (curnode!=null) {k--;curnode=curnode.next;}if (k==0) { head=head.next;}if (k<0) {curnode = head;while (++k!=0) {curnode=curnode.next;}curnode.next = curnode.next.next;}return head;}public void print(Node head) {Node node = head;while (node!=null) {System.out.println(node.data);node=node.next;}}public static void main(String[] args) {Node head = new Node(1);head.next = new Node(5);head.next.next = new Node(10);head.next.next.next = new Node(25);head.next.next.next.next = new Node(30);DeleteLastSlink deleteLastSlink = new DeleteLastSlink();deleteLastSlink.print(head);System.out.println("-----");deleteLastSlink.deleteLast(head, 3);deleteLastSlink.print(head);}}

public class DeleteLastDlink {public static class Node {int data;Node previous;Node next;public Node(int data) {this.data = data;}}public Node deleteLast(Node head,int k) {if (head == null && k<1) {return head;}Node curnode = head;while (curnode!=null) {k--;curnode = curnode.next;}if (k==0) {head = head.next;}if (k<0) {curnode = head;while (++k!=0) {curnode = curnode.next;}curnode.next.next.previous = curnode;curnode.next  = curnode.next.next;}return head;}public void print(Node head) {Node node = head;while (node!=null) {System.out.println(node.data);node=node.next;}}public static void main(String[] args) {Node head = new Node(1);head.next = new Node(3);head.next.next = new Node(5);head.next.next.next = new Node(7);head.next.next.next.next = new Node(9);DeleteLastDlink deleteLastDlink = new DeleteLastDlink();deleteLastDlink.print(head);System.out.println("-----------");deleteLastDlink.deleteLast(head, 3);deleteLastDlink.print(head);}}

题目：

给定链表的头节点head，实现删除链表中间节点的函数。

如： 1-》2，删除1 1-》2-》3，删除2 1-》2-》3-》4，删除2

public class RemoveMidNode {public static class Node{int data;Node next;public Node(int data) {this.data = data;}}public Node removeMid(Node head) {if (head.next.next==null) {return head.next;}if (head==null && head.next==null) {return head;}Node pre = head;Node cur = head.next.next;while (cur.next!=null && cur.next.next!=null) {pre=pre.next;cur = cur.next.next;}pre.next = pre.next.next;return head;}public void print(Node head) {Node node = head;while (node!=null) {System.out.println(node.data);node=node.next;}}public static void main(String[] args) {Node head = new Node(1);head.next = new Node(3);head.next.next = new Node(5);head.next.next.next = new Node(7);head.next.next.next.next = new Node(9);RemoveMidNode removeMidNode = new RemoveMidNode();removeMidNode.print(head);System.out.println("-------------");removeMidNode.removeMid(head);removeMidNode.print(head);}}