有没有会的帮改一下代码

这个程序没有报错，就是不输出，运行完还一卡一卡的

#include
#include
int main()
{
    struct node
        
    {
        int data;
        struct node *next;
    }; 
    struct node *p,*q,*s,*head,*d,*o;
    p=(struct node *)malloc(sizeof(struct node));
    q=(struct node *)malloc(sizeof(struct node));
   s =(struct node *)malloc(sizeof(struct node));
    int x,y;
    head=p;
    while(x!=-1)
    {
        scanf("%d",&x);
        p->data=x;
        p=p->next;
            
    }
    
  d=q;
    
     while(y!=-1)
    {
        scanf("%d",&y);
        q->data=y;
        q=q->next;}
    
    o=s;
    while(head->next!=NULL&&d->next!=NULL)
    {
        if(head->datadata)
        {
            s->data=head->data;
            head=head->next;
            s=s->next;
        }
      else  if(head->data>d->data)
        {
            s->data=d->data;
            d=d->next;
            s=s->next;
        }
        
        
    }
    if(d->data!=NULL)
    {s=d;
}
    if(head->data!=NULL)
    {
        s=head;
    }
    while(o)
    {
        printf("%d",o->data);
        if(o->next)
            printf(" ");
    }
}

修改如下，供参考：

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

struct node* create()
{
    int x;
    struct node* head = NULL, * p = NULL;
    while (1)
    {
        scanf("%d", &x);
        if (x == -1) break;
        if (head == NULL) {
            head = p = (struct node*)malloc(sizeof(struct node));
            head->data = x;
            head->next = NULL;
        }
        else {
            p->next = (struct node*)malloc(sizeof(struct node));
            p->next->next = NULL;
            p->next->data = x;
            p = p->next;
        }
    }
    return head;
}

struct node* combin(struct node** L1, struct node** L2)
{
    struct node* p1 = (*L1), * p2 = (*L2), * tail = NULL, * head = NULL, * p;
    if ((*L1) == NULL && (*L2) == NULL) {  //如果 L1 L2 都为空链表
        return NULL;
    }
    if ((*L1) && (*L2)) {    // 如果L1 L2 都不是空链表
        while (p1 && p2) {
            if (p1->data > p2->data) {
                p = p2;
                p2 = p2->next;
            }
            else {
                p = p1;
                p1 = p1->next;
            }
            if (head == NULL)
                head = p;
            else
                tail->next = p;
            tail = p;
        }
        tail->next = p1 ? p1 : p2;
    }
    else {   // L1 L2 其中一个为空链表
        head = (*L1) ? (*L1) : (*L2);
    }
    (*L1) = NULL; (*L2) = NULL;
    return head;
}
void print(struct node* head)
{
    struct node* p = head;
    if (!head) {
        printf("NULL\n");
    }
    else{
        while (p) {
            printf(p == head ? "%d" : " %d", p->data);
            p = p->next;
        }
        printf("\n");
    }
}

int main()
{
    struct node* head1 = NULL, * head2 = NULL, * head3 = NULL;
    head1 = create();
    head2 = create();
    head3 = combin(&head1, &head2);
    print(head3);
    return 0;
}

最后的while循环中，你的o指向没改变啊，不就死循环了。
o=o->next

输入的时候 p=p->next;，这个p->next;可是NULL，这里需要分配内存保存输入的数据。
整个程序就分配了3个头结点的内存，其他节点都没有分配内存。