单链表，为什么达不到我想要的效果😭

#include<stdio.h>
#include<stdlib.h>
typedef struct girl{
char name[20];
int classnumber;
int number;
}girl;
typedef struct stu{
girl data;
struct stu* next;
}stu;
//创建链表
stucreatlink(){
stu headlink=(stu*)malloc(sizeof(stu));
headlink->next =NULL;
return headlink;
}
//创建链接
stu creatnewnode(girl data){
stu newnode=(stu*)malloc(sizeof(stu));
newnode->data =data;
newnode->next =NULL;
return newnode;
}
//从头插入链表
void insert(stuheadlink,girl data){
stu newnode =creatnewnode(data);
newnode->next =headlink->next ;
headlink->next =newnode;
}
//打印链表
void printlink(stu* headlink){
stu* p=headlink->next ;
while(p->next !=NULL){
printf("%s\t%d\t%d\n",p->data.name ,p->data.classnumber ,p->data.number );
p=p->next ;
}
}
//搜索连节
/struct/
void seeklink(stu *headlink,char name){
stu p=headlink->next ;
while(p->data.name !=name){
p=p->next ;
}
printf("%s\t%d\t%d\n",p->data.name ,p->data.classnumber ,p->data.number );
}

//删除链表
void deletelink(stu* headlink, girl data ){
stu* p=headlink;
stu* beforep=headlink->next;
while(p!=NULL){
if(p->data.name !=data.name )
beforep=p;
p=p->next ;
break;
}
beforep->next =p->next ;
free(p);
}
int main (){
int i=0;
girl g;
stu*head=creatlink();
for(i=0;i<5;i++){
scanf("%s%d%d",g.name ,g.classnumber ,g.number );
insert(head,g);
}
printlink(head);
return 0;
}

修改如下，供参考：

#include<stdio.h>
#include<stdlib.h>
typedef struct girl {
    char name[20];
    int  classnumber;
    int  number;
}girl;
typedef struct stu {
    girl data;
    struct stu* next;
}stu;
//创建链表
stu *creatlink() {
    stu *headlink = (stu*)malloc(sizeof(stu));
    headlink->next = NULL;
    return headlink;
}
//创建链接
stu *creatnewnode(girl data) {
    stu *newnode = (stu*)malloc(sizeof(stu));
    newnode->data = data;
    newnode->next = NULL;
    return newnode;
}
//从头插入链表
void insert(stu *headlink, girl data) {
    stu *newnode = creatnewnode(data);
    newnode->next = headlink->next;
    headlink->next = newnode;
}
//打印链表
void printlink(stu* headlink) {
    stu* p = headlink->next;
    while (p != NULL) {      //(p->next != NULL)
        printf("%s\t%d\t%d\n", p->data.name, p->data.classnumber, p->data.number);
        p = p->next;
    }
}
//搜索连节
//struct /
void seeklink(stu * headlink, char *name) {
    stu *p = headlink->next;
    while (p && strcmp(p->data.name, name) != 0) {  //while (p->data.name != name)
        p = p->next;
    }
    if (p != NULL)
        printf("\n%s\t%d\t%d\n", p->data.name, p->data.classnumber, p->data.number);
    else
        printf("not found!\n");
}

//删除链表
void deletelink(stu* headlink, char* name) {
    stu* p = headlink->next;
    stu* beforep = headlink;
    while (p != NULL) {
        if (strcmp(p->data.name, name) != 0) { //if (p->data.name != data.name)
            beforep = p;
            p = p->next;
        }
        else
            break;
    }
    if (p != NULL) {
        beforep->next = p->next;
        free(p);
    }
    else
        printf("not found!\n");
}
int main() {
    int i = 0;
    girl g;
    stu* head = creatlink();
    for (i = 0; i < 5; i++) {
        scanf("%s%d%d", g.name, &g.classnumber, &g.number); //scanf("%s%d%d", g.name, g.classnumber, g.number);
        insert(head, g);
    }
    printlink(head);
    return 0;
}

删除链表：1. 现在删除逻辑是不等于时删除 2.有个问题，当p=null时，p->next 是有问题的
打印链表: 这样试试

void printlink(stu* headlink){
  stu* p=headlink;
while(p !=NULL){
printf("%s\t%d\t%d\n",p->data.name ,p->data.classnumber ,p->data.number );
p=p->next ;
}
}