链表有序合并，运行错误

问题遇到的现象和发生背景

用代码块功能插入代码，请勿粘贴截图

我想要达到的结果

不知道为什么Lc无法打印

#include
#include
#include
typedef struct node {//定义结点
    int data;//结点数据域
    struct node* next;//结点指针域
}node, * Linklist;
void creatList_1(node* l,int n) {//头插法
    l->next = NULL;
    node *p;//设置一个结点指针
    int i = 1;
    int j;
    for (i = n;i > 0;--i) {
        p = (Linklist)malloc(sizeof(node));//动态分配内存
        scanf_s("%d", &j);
        p->data = j;
        p->next = l->next;
        l->next = p;
    }
}
void creatList_2(node* l,int n) {
        l->next = NULL;
        node* p;
        node* r;
        int i = 1;
        int j;
        r = l;
    for(i=1;i<=n;++i){
           p = (Linklist)malloc(sizeof(node));
           scanf_s("%d", &j);
           p->data = j;
           p->next = r->next;
           r->next = p;//尾指针的指针域指向新结点p
           r = p;//尾指针永远在最后 
            }
}
void MergeList_L(node* l1, node* l2, node* l3) {
    node* p1, * p2, * p3;
    p1 = l1->next;
    p2 = l2->next;
    p3 = l1;
    l3 = p3;
    while (p1 && p2) {
        if (p1->data<= p2->data)
        {
            p3->next = p1;
            p3 = p1;
            p1 = p1->next;
        }
        else 
        {
            p3->next = p2;
            p3 = p2;
            p2 = p2->next;
        }
    }
    p3->next = p1 ? p1 : p2;
    free(l2);
}

void PrintList(node* l) {
    printf("内容为");
    while (l->next != NULL) 
    {
        printf("%d ", l->next->data);
        l = l->next;
    }
    printf("\n");
}
void main() {
    Linklist La, Lb, Lc;
    La = (node*)malloc(sizeof(node));//动态分配内存
    Lb = (node*)malloc(sizeof(node));
    Lc = (node*)malloc(sizeof(node));
    Lc->next = NULL;
    creatList_1(La,7);//头插法，倒序
    creatList_2(Lb,5);//尾插法，正序
    MergeList_L(La, Lb, Lc);
    PrintList(Lc);
}

#include<stdio.h>
#include<stdlib.h>
#include<malloc.h>
typedef struct node {//定义结点
    int data;//结点数据域
    struct node* next;//结点指针域
}node, * Linklist;
void creatList_1(node* l,int n) {//头插法
    l->next = NULL;
    node *p;//设置一个结点指针
    int i = 1;
    int j;
    for (i = n;i > 0;--i) {
        p = (Linklist)malloc(sizeof(node));//动态分配内存
        scanf_s("%d", &j);
        p->data = j;
        p->next = l->next;
        l->next = p;
    }
}
void creatList_2(node* l,int n) {
        l->next = NULL;
        node* p;
        node* r;
        int i = 1;
        int j;
        r = l;
    for(i=1;i<=n;++i){
           p = (Linklist)malloc(sizeof(node));
           scanf_s("%d", &j);
           p->data = j;
           p->next = r->next;
           r->next = p;//尾指针的指针域指向新结点p
           r = p;//尾指针永远在最后 
            }
}
void MergeList_L(node* l1, node* l2, node** l3) {
    node* p1, * p2, * p3;
    p1 = l1->next;
    p2 = l2->next;
    p3 = l1;

    while (p1 && p2) {
        if (p1->data<= p2->data)
        {
            p3->next = p1;
            p3 = p1;
            p1 = p1->next;
        }
        else 
        {
            p3->next = p2;
            p3 = p2;
            p2 = p2->next;
        }
    }
    p3->next = p1 ? p1 : p2;
    free(l2);
    *l3 = l1;
}
 
void PrintList(node* l) {
    printf("内容为");
    while (l->next != NULL) 
    {
        printf("%d ", l->next->data);
        l = l->next;
    }
    printf("\n");
}
void main() {
    Linklist La, Lb, Lc;
    La = (node*)malloc(sizeof(node));//动态分配内存
    Lb = (node*)malloc(sizeof(node));
    creatList_1(La,3);//头插法，倒序
    creatList_2(Lb,3);//尾插法，正序
    MergeList_L(La, Lb, &Lc);
    PrintList(Lc);
}
 

改动处见注释，供参考：

#include<stdio.h>
#include<stdlib.h>
#include<malloc.h>
typedef struct node {//定义结点
    int data;//结点数据域
    struct node* next;//结点指针域
}node, * Linklist;
void creatList_1(node* l,int n) {//头插法
    l->next = NULL;
    node *p;//设置一个结点指针
    int i = 1;
    int j;
    for (i = n;i > 0;--i) {
        p = (Linklist)malloc(sizeof(node));//动态分配内存
        scanf_s("%d", &j);
        p->data = j;
        p->next = l->next;
        l->next = p;
    }
}
void creatList_2(node* l,int n) {
    l->next = NULL;
    node* p;
    node* r;
    int i = 1;
    int j;
    r = l;
    for(i=1;i<=n;++i){
           p = (Linklist)malloc(sizeof(node));
           p->next = NULL;   //修改
           scanf_s("%d", &j);
           p->data = j;
                             //p->next = r->next; 修改
           r->next = p;//尾指针的指针域指向新结点p
           r = p;//尾指针永远在最后
    }
}
void MergeList_L(node* l1, node* l2, node* l3) {
    node* p1, * p2, * p3;
    p1 = l1->next;
    p2 = l2->next;
    p3 = l3;   //p3 = l1;修改
               //l3 = p3;修改
    while (p1 && p2) {
        if (p1->data<= p2->data)
        {
            p3->next = p1;
            p3 = p1;
            p1 = p1->next;
        }
        else
        {
            p3->next = p2;
            p3 = p2;
            p2 = p2->next;
        }
    }
    p3->next = p1 ? p1 : p2;
    free(l2);
    free(l1);   //修改
}
 
void PrintList(node* l) {
    printf("内容为");
    while (l->next != NULL)
    {
        printf("%d ", l->next->data);
        l = l->next;
    }
    printf("\n");
}
void main() {
    Linklist La, Lb, Lc;
    La = (node*)malloc(sizeof(node));//动态分配内存
    Lb = (node*)malloc(sizeof(node));
    Lc = (node*)malloc(sizeof(node));
    Lc->next = NULL;
    creatList_1(La,7);//头插法，倒序
    creatList_2(Lb,5);//尾插法，正序
    MergeList_L(La, Lb, Lc);
    PrintList(Lc);
}

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这个是否有问题
https://ask.csdn.net/questions/7786034