这个程序运行后为什么会出现乱码呢，求大神指教

#include <stdio.h>
#include <stdlib.h>

/* run this program using the console pauser or add your own getch, system("pause") or input loop */
typedef struct student
{
    char name[20];
    int  score;
    struct student* next;
}stu;
//创建链表
struct student* creat(int n)
{
    int i;
    stu* head;
    stu* note;
    stu* end;
    (stu*)malloc(sizeof(stu));
    head=end=NULL;
    for(i=0;i<n;i++)
    {
        note=(stu*)malloc(sizeof(stu));
        printf("请输入学生姓名\n");
        scanf("%s",note->name);
        printf("请输入学生分数\n");
        scanf("%d",&note->score);
        if(head==NULL)
        {
            head=note;
        }
        else
        {
            end->next=note;   
        }
        end=note;
    }
    end->next=NULL;
    return head;
}
//链表基本操作之插入节点
struct student* addnote(stu* head,int m)
{
    int i;
    stu* p;
    stu* q;
    p=head;
    for(i=0;i<m;i++)
    {
        p=p->next;
    }
    q=(stu*)malloc(sizeof(stu));
    printf("请输入插入节点的学生姓名\n");
    scanf("%s",p->name);
    printf("请输入插入节点的学生成绩\n");
    scanf("%d",&p->score);
    q->next=p->next;
    p->next=q;
    return head;
}

//链表基本操作之删除节点
struct student* deletenote(stu* head,int k)
{
    int i;
    stu* p;
    stu* q;
    p=q=head;
    for(i=1;i<=k;i++)
    {
        p=p->next;
    }
    for(i=1;i<=k-1;i++)
    {
        q=q->next;
    }
        q->next=p->next;
        free(p);
    return head;
}
//链表操作之遍历链表
void outputlist(stu* head)
{
    stu* p;
    p=head;
    while(p!=NULL)
    {
        printf("姓名:%s\n",p->name);
        printf("成绩:%d\n",p->score);
        p=p->next;
    }
    return;
}
int main(int argc, char *argv[]) {
    int n,m,k;
    stu* head;
    printf("请输入要输入学生的个数\n");
    scanf("%d",&n);
    head=creat(n);
    printf("请输入要增加节点的位置\n");
    scanf("%d",&m);
    addnote(head,m);
    printf("请输入要删除节点的位置\n");
    scanf("%d",&k);
    deletenote(head,k);
    outputlist(head);
    return 0;
   
}
//求大神执教，错在哪里了