为什么会出现有乱码的呢？而且输出也有问题。。
求高手解答

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
typedef struct student
{
    char name[20];
    char sno[13];
    int mark;
 }student;

typedef struct Node
{
    student studentInfo;
    struct Node *next;
}LinkList;

LinkList *input()
{
    LinkList *s;
    s=(LinkList *)malloc(sizeof(LinkList));
    s->next=0;
    return s;
}

void insert(LinkList *stu,LinkList *stulist)
{
    LinkList *pointer = stulist;
    LinkList *stupointer =stulist->next;

    while(stupointer!=0&& stupointer->studentInfo.mark<=stu->studentInfo.mark)
    {
        pointer =stupointer;
        stupointer=stupointer->next;
    }
    pointer->next=stu;
    stu->next =stupointer;
}



int search(LinkList *L, char sno[13])
{

    LinkList *S = L,*P;
    while(S && (strcmp(S->studentInfo.sno, sno) != 0))
       S = S->next;
    if(!S->next)
        printf("NO FIND!\n");
    else
    {
        P = S->next;
        S->next = P->next;
        free(S);
    }
    return 0;
}

void main()
{
    LinkList *stulist,*stu,*stupointer;
    stulist=input();
    stu=(LinkList *)malloc(sizeof(LinkList));
    printf("插入3个学生");
    strcpy(stu->studentInfo.sno,"001");
    strcpy(stu->studentInfo.name,"张1");
    stu->studentInfo.mark=90;
    stu->next=0;
    insert(stu,stulist);

    stu=(LinkList *)malloc(sizeof(LinkList));
    strcpy(stu->studentInfo.sno,"002");
    strcpy(stu->studentInfo.name,"张2");
    stu->studentInfo.mark=85;
    stu->next=0;
    insert(stu,stulist);

    stu=(LinkList *)malloc(sizeof(LinkList));
    strcpy(stu->studentInfo.sno,"003");
    strcpy(stu->studentInfo.name,"张3");
    stu->studentInfo.mark=87;
    stu->next=0;
    insert(stu,stulist);
    stupointer=stulist;

    while(stupointer!=0)
    {
        printf("%s,%s,%d\n",stupointer->studentInfo.sno,stupointer->studentInfo.name
                            ,stupointer->studentInfo.mark);

        stupointer=stupointer->next;
    }
    printf("\n");

    printf("删除一个学号为001的学生后：\n");
    search(stu,"001");
    while(stupointer!=0)
    {
        printf("%s,%s,%d\n",stupointer->studentInfo.sno,stupointer->studentInfo.name
                            ,stupointer->studentInfo.mark);

        stupointer=stupointer->next;
    }

}

似乎不是这里出问题的

    printf("删除学号为002学生后：\n");
    search(stu,"002");
    stupointer = stulist->next;

    while(stupointer!=0)
    {
        printf("%s,%s,%d\n",stupointer->studentInfo.sno,stupointer->studentInfo.name
                            ,stupointer->studentInfo.mark);

        stupointer=stupointer->next;

我加了这句后能显示输出，但他不能按输入的学号删除
//删除功能
int search(LinkList *L, char sno[13])
{

    LinkList *S = L, *P;
    while(S && (strcmp(S->studentInfo.sno, sno) != 0))
       S = S->next;
    if(!S->next)
        printf("NO FIND!\n");  
    else
    {
        P = S->next;
        S->next = P->next;
        free(P);

    }
    return 0;
}

非常感谢啊·~~不是英文不好，只是因为当时想实现搜索功能，后来放弃了，没改掉而已