c语言指针，有关指向指针

编译没有错误，运行错误
是哪里出了问题


#include <stdio.h>
#include <stdlib.h>
#define N 5

//Node ????
typedef struct node
{
    int data;
    struct node * next;
}Node;

int main()
{

    int creatListFromTail(Node ** pfirst);
    void outputList(Node * phead);
    void freeList(Node **pfirst);
    Node *insertNode(Node * head,int newdata);
    

    Node * phead=NULL;
    int x;
    

    if(creatListFromTail(&phead)!=0)
    {
    
        outputList(phead);
        
    
        scanf("%d",&x ); 
        phead=insertNode(phead, x);
        outputList(phead);
        
        
        freeList(&phead);
    }
    return 0;
}

int creatListFromTail(Node ** pfirst){
    int c;
    Node*p,*q;
    int i;
    for(i=1;i<=N;i++){
        scanf("%d",&c);
        p = (Node*)malloc(sizeof(Node));
        p->data = c;
        p->next = NULL;
        if(i==1){
            q = p;
            *pfirst = p;
        } 
        else {
            q->next = p;
            q = p;
        } 
        
    }
    return 1;
}
void outputList(Node * phead){
    Node*p;
    p = phead;
    while(phead){
        printf("%d->",p->data);
        p = p->next;
    } 
}
void freeList(Node **pfirst){
    Node*p;
    Node*q;
    q = *pfirst;
    while(q){
        p = q;
        q = q->next;
        free(p);
    }
}
Node *insertNode(Node * head,int newdata){
    Node*p;
    Node*q;
    p = head;
    q = p;
    while(1)
{
        if(newdata>p->data&&q==p){
            p = (Node*)malloc(sizeof(Node));
            p->data = newdata;
            p->next = head;
            break;
        }
        if(newdata<p->data){
            q = p;
            p = p->next;
            
        }
        else{
            p = (Node*)malloc(sizeof(Node));
            p->data = newdata;
            p->next = q->next;
            q->next = p;
            break;
        }    
    
    
    
}
return p;
}

这个函数 改一下 ：

void outputList(Node * phead){
    Node*p;
    p = phead;
    while(p){
        printf("%d->",p->data);
        p = p->next;
    } 
}

void outputList(Node * phead) 输出链表函数里，while(phead) 应修改为：while(p) ，插入函数：Node *insertNode(Node * head,int newdata) 也存在问题，整体修改如下，供参考：

#include <stdio.h>
#include <stdlib.h>
#define N 5

typedef struct node
{
    int    data;
    struct node * next;
}Node;

int main()
{

    int creatListFromTail(Node ** pfirst);
    void outputList(Node * phead);
    void freeList(Node **pfirst);
    Node *insertNode(Node * head,int newdata);

    Node * phead=NULL;
    int x;

    if(creatListFromTail(&phead)!=0)
    {
        outputList(phead);

        printf("\n");

        scanf("%d",&x );
        phead=insertNode(phead, x);
        outputList(phead);

        printf("\n");

        freeList(&phead);
    }
    return 0;
}

int creatListFromTail(Node ** pfirst){
    int c;
    Node*p,*q;
    int i;
    for(i=1;i<=N;i++){
        scanf("%d",&c);
        p = (Node*)malloc(sizeof(Node));
        p->data = c;
        p->next = NULL;
        if(i==1){
            q = p;
            *pfirst = p;
        } 
        else {
            q->next = p;
            q = p;
        }
    }
    return 1;
}
void outputList(Node * phead){
    Node*p;
    p = phead;
    while(p){   //while(phead) 修改
        printf("%d->",p->data);
        p = p->next;
    } 
}
void freeList(Node **pfirst){
    Node*p;
    Node*q;
    q = *pfirst;
    while(q){
        p = q;
        q = q->next;
        free(p);
    }
}
Node *insertNode(Node * head,int newdata){
    Node*p;
    Node*q,*t; // 修改
    p = head;
    q = p;
    while(p) // while(1) 修改
    {
        if(newdata >= p->data){ //if(newdata > p->data && q == p)
               //t = (Node*)malloc(sizeof(Node));//p = (Node*)malloc(sizeof(Node));
               //t->data = newdata; //p->data = newdata;
               //t->next = head;   //p->next = head;
            break;
        }
        else { //if(newdata<p->data)
            q = p;
            p = p->next;
        }
    }
        //if(newdata >= p->data){
    t = (Node*)malloc(sizeof(Node));// p = (Node*)malloc(sizeof(Node));
    t->data = newdata;  //p->data = newdata;
    if (head == p){
        t->next = head;
        head = t;
    }
    else{
        t->next = q->next;  //p->next = q->next;
        q->next = t;        //q->next = p;
    }
        //    break;
        //}
    return head;  //return p;
}