能帮我看看我这个删除链表错在哪了吗

#include<stdio.h>
#include<stdlib.h>
struct stu{
int num;
int scores;
struct stunext;};
struct stukiang(){
struct stu*head,*tail,p;
int num;
head=tail=NULL;
scanf("%d",&num);
while(num){
p=(struct stu)malloc(sizeof(struct stu));
scanf("%d",&p->num);
scanf("%d",&p->scores);
p->next=NULL;
if(head==NULL)
head=p;
else
tail->next=p;
tail=p;
num--;}
return head;}
int main(){
struct stu *head,*o,*p1,*p2;
int n;
scanf("%d",&n);
head=kiang();
p1=head;
p2=head->next;
if(head->num==n)
{o=head;
head=head->next;
}
while(p2!=NULL)
if(p2->num==n)
{p1->next=p2->next;
break;}
else
{p1=p2;
p2=p2->next;}
while(head!=NULL)
{printf("%d %d\n",head->num,head->scores);
head=head->next;}
return 0;}

这三处均是指针，分别改为
struct stu *next;
*p;
p=(struct stu *)malloc

没问题啊 题主你用的什么测试用例

修改如下，供参考：

#include <stdio.h>
#include <stdlib.h>
struct stu {
    int num;
    int scores;
    struct stu* next;
};
struct stu* kiang() 
{
    struct stu* head, * tail, * p;
    int num;
    head = tail = NULL;
    scanf("%d", &num);
    while (num) {
        p = (struct stu*)malloc(sizeof(struct stu));
        scanf("%d", &p->num);
        scanf("%d", &p->scores);
        p->next = NULL;
        if (head == NULL)
            head = p;
        else
            tail->next = p;
        tail = p;
        num--;
    }
    return head;
}

int main() {
    struct stu* head, * o, * p1, * p2;
    int n;
    head = kiang();
    scanf("%d", &n);//修改
    p1 = NULL;      //修改
    p2 = head;      //修改
    while (p2 != NULL) //修改
    {
        if (p2->num == n)
        {
            if (!p1) {        //修改
                o = head;
                head = head->next;
                free(o);
            }
            else {           //修改 
                p1->next = p2->next;
                free(p2);
                p2 = p1->next;
            }
        }
        else{               //修改
            p1 = p2;
            p2 = p2->next;
        }
    }
    p1 = head;
    while (p1 != NULL)
    {
        printf("%d %d\n", p1->num, p1->scores);
        p1 = p1->next;
    }
    return 0;
}