链表的合并（1） - 编程论坛

先生成两个链表。在对两个链表进行合并，并从小到大排序
代码一：

程序代码：

#include<iostream>
using namespace std;
struct student{

int num;

int score;

student* next;

};
student * creat(int N){
student *ne;
ne=new student;
cin>>ne->num>>ne->score;
ne->next=NULL;
student*head;
head =ne;
student *p1;
p1=head;
student *p0;
for(int i=1;i!=N;++i){
ne=new student;
cin>>ne->num>>ne->score;
while((ne->num>p1->num)&&(p1->next!=NULL)){
    p0=p1;
    p1=p1->next;
}
if(ne->num<=p1->num){
    if(head==p1)head=ne;
    else p0->next=ne;
    ne->next=p1;
}else{
    p1->next=ne;
    ne->next=NULL;
}
}

return (head);
}

student *hebi(student* head,student *h2)
{
while(h2!=NULL){
student *p1,*ne,*p0;
ne=new student;
ne=h2;
p1=head;
while((ne->num>p1->num)&&(p1->next!=NULL)){
    p0=p1;
    p1=p1->next;
}
if(ne->num<=p1->num){
    if(head==p1)head=ne;
    else p0->next=ne;
    ne->next=p1;
}else{
    p1->next=ne;
    ne->next=NULL;
}
h2=h2->next;

}
return head;

}



void print(student * head){
    student *p;
    p=head;
    do{
        cout<<p->num<<" "<<p->score<<endl;
        p=p->next;
    }while(p!=NULL);
}
int main(){
    int N,M;
    cin>>N>>M;
    student *head1,*head2;
    head1=creat(N);
   head2=creat(M);
hebi(head1,head2);
print(head1);

return 0;


}

自己感觉这样也是对的，但是输入数据之后，无法达到合并并排序的效果，
代码二

程序代码：

#include<iostream>
using namespace std;
struct student{

int num;

int score;

student* next;

};
student * creat(int N){
student *ne;
ne=new student;
cin>>ne->num>>ne->score;
ne->next=NULL;
student*head;
head =ne;
student *p1;
p1=head;
student *p0;
for(int i=1;i!=N;++i){
ne=new student;
cin>>ne->num>>ne->score;
while((ne->num>p1->num)&&(p1->next!=NULL)){
    p0=p1;
    p1=p1->next;
}
if(ne->num<=p1->num){
    if(head==p1)head=ne;
    else p0->next=ne;
    ne->next=p1;
}else{
    p1->next=ne;
    ne->next=NULL;
}
}

return (head);
}

student *hebi(student* head,student *h2)
{student *p1,*ne,*p0;
while(h2!=NULL){

ne=new student;
ne->num=h2->num;
ne->score=h2->score;
h2=h2->next;
p1=head;
while((ne->num>p1->num)&&(p1->next!=NULL)){
    p0=p1;
    p1=p1->next;
}
if(ne->num<=p1->num){
    if(head==p1)head=ne;
    else p0->next=ne;
    ne->next=p1;
}else{
    p1->next=ne;
    ne->next=NULL;
}
}
return (head);

}



void print(student * head){
    student *p;
    p=head;
    do{
        cout<<p->num<<" "<<p->score<<endl;
        p=p->next;
    }while(p!=NULL);
}
int main(){
    int N,M;
    cin>>N>>M;
    student *head1,*head2;
    head1=creat(N);
   head2=creat(M);
   cout<<endl;
   print(head1);
   print(head2);
   cout<<endl;
hebi(head1,head2);
print(head1);

return 0;


}

我把指针的数据先提出来，然后再插入，但在测试数据的时候
输入
2 3
2 4
1 2
3 2
4 1
5 2

输出
1 2
2 4
3 2
4 1
5 2

但输入
2 3
4 3
3 2
2 5
1 3
3 2

输出
3 2
4 3
以及其他数据都无法输出正确结果；
有的程序还会崩溃；
有谁能帮我看看问题出在哪；