#include<stdio.h>
#include<stdlib.h>
struct node{
	int data;
	struct node*next;
};

struct node*create(int len,int a[]){
	struct node*head=(struct node*)malloc(sizeof(struct node));
	struct node*pre=head;
	int i;
	for(i=0;i<len;i++){
		struct node*now=(struct node*)malloc(sizeof(struct node));
		now->data=a[i];
		pre->next=now;
		pre=now;
		pre->next=NULL;//这条语句得加上，不然会有问题
	}
	return head;
}

struct node*merge(struct node*L1,struct node*L2){
	struct node*head=(struct node*)malloc(sizeof(struct node));
	struct node*pre=head;
	while(L1!=NULL&&L2!=NULL){
		if(L1->data<L2->data){
			pre->next=L1;
			pre=L1;
			L1=L1->next;
		}else{
			pre->next=L2;
			pre=L2;
			L2=L2->next;
		}
	}
	while(L1!=NULL){
		pre->next=L1;
		pre=L1;//记得加上这条语句
		L1=L1->next;
	}
	while(L2!=NULL){
		pre->next=L2;
		pre=L2;
		L2=L2->next;
	}
	return head->next;
}
int main(){
	int s1,s2,i;
...