头插法、尾差法创建单链表及其合并

package 数据结构;

import java.util.Scanner;
/**
* 带头结点的链表的创建
* @author wky
*
*/
class LNode{
int data;
LNode next;
}
public class 链表操作 {
//头插法创建链表
static LNode create_list_front(int n){
LNode head,p;
head = new LNode();
head.next = null;
for(int i=0;i<n;i++){
p = new LNode();
System.out.println("input elems(list_front):");
Scanner scn = new Scanner(System.in);
p.data = scn.nextInt();
p.next = head.next;
head.next = p;
}
return head;
}

//尾插法
static LNode create_list_rear(int n){
LNode s,r;//s指向新申请的节点，而r指向链表最新的终端节点
LNode head;
head = new LNode();
head.next = null;
r = head;//r指向head节点，此时head节点就是终端节点
for(int i=0;i<n;i++){
s = new LNode();
System.out.println("input elems(list_rear):");
Scanner scn = new Scanner(System.in);
s.data = scn.nextInt();
r.next = s;//用r来接纳新的节点
r = r.next;//r指向终端节点
}
r.next = null;
return head;
}
//打印链表
static void print_list(LNode head){
LNode p;
p = head.next;
while(p!=null){
System.out.print(p.data+",");
p = p.next;
}
}

//两个有序链表合并
static LNode merge_list(LNode la,LNode lb,LNode lc){
LNode pa,pb,pc;
pa = la.next; //pa,pb,pc 相当于一个跟踪标识号。
pb = lb.next;
pc = lc;
while((pa!=null)&&(pb!=null)){
if(pa.data<=pb.data){
pc.next = pa;
pc = pc.next;
pa = pa.next;
}else{
pc.next = pb;
pc = pc.next;
pb = pb.next;
}
}
pc.next = null;
if(pa!=null) pc.next = pa;
if(pb!=null) pc.next = pb;
return lc;
}
public static void main(String[] args){
LNode la;
LNode lb;
LNode lc;
lc = new LNode();
la = create_list_rear(5);
lb = create_list_rear(6);
lc = merge_list(la,lb,lc);
System.out.println("l1:");
print_list(la);
System.out.println("l2:");
print_list(lb);
System.out.println("l3:");
print_list(lc);
}

}