C语言程序设计中链表问题

Question

程序设计我想做一个学生考勤系统

此为结构体要素（几乎大部分功能函数无误可忽略）

此为读文件代码

此为终端输出和保存数据代码

运行后输入5 会出现一行无学生信息的文字

后输入1 添加一名学生信息

后输入5 再次查看 信息已输入但是无信息文字还在

随后输入8保存后输入9退出 查看文本 文本中存在刚刚输入的一项信息

后再次打开程序 输入5查看 原本发现无信息文字被所输入信息填满 即第一条输入的学生信息会重复两次

后续大量数据发现 只有第一个输入的学生信息会被重复两遍 其余功能均正常使用 而在show函数中多添加一个pr=pr->next就能只输出一个首位学生信息
本人 感觉问题会不会feof（）导致多读一行重复了
求帮忙看看 以及怎么修改 以下是源码

#include"Attendance system.h";
int sum1 = 0, sum2 = 0, sum3 = 0;

char xuehao[100];//学号
char name[100];//姓名
char banji[100];//班级
char data[100];//时间
char daoke[10];//到课情况
char num[100][30];//存储一共有多少学号
char num2[100][30];//存储一共有多少姓名以便后面排序使用
char num3[100][30];//存储时间

void creatnewnode(node*& student)
{
    student = (node*)malloc(sizeof(node));
    student->next = NULL;
}

void insert(node*& L, node* p)
{
    node* q = NULL;
    q = L;
    p->next = q->next;
    q->next = p;
}

void read(node* L)
{
    FILE* FP;
    FP = fopen("data.txt", "rb");
    if (FP == NULL)
    {
        printf("该文件不存在！");
        exit(0);//终止程序 
    }
    while (!feof(FP))
    {
        node* pr = L;
        node* p=NULL;
        node* l = (node*)malloc(sizeof(node));//创建节点中转信息
        fscanf(FP, "%s%s%s%s%s", xuehao, name, banji, data, daoke);
        strcpy(l->data.xuehao, xuehao);
        strcpy(l->data.name, name);
        strcpy(l->data.banji, banji);
        strcpy(l->data.data, data);
        strcpy(l->data.daoke, daoke);
        int flag = 1, flag2 = 1, flag3 = 1;
        for (int i = 0; i <= sum1; i++)
        {
            if (strcmp(num[i], xuehao) == 0)
            {
                flag = 0;
            }
        }
        if (flag)
        {
            strcpy(num[sum1], xuehao);
            sum1++;
        }
        for (int i = 0; i <= sum2; i++)
        {
            if (strcmp(num2[i], name) == 0)
            {
                flag2 = 0;
            }
        }
        if (flag2)
        {
            strcpy(num2[sum2], name);
            sum2++;
        }
        for (int i = 0; i <= sum3; i++)
        {
            if (strcmp(num3[i], data) == 0)
            {
                flag3 = 0;
            }
        }
        if (flag3)
        {
            strcpy(num3[sum3], data);
            sum3++;
        }
        insert(L, l);
        l = l->next;
    }
    fclose(FP);

}

void search(node* student) 
{
    node* pr = student->next;
    printf("输入1按学号查询，输入2按姓名查询，输入3按考勤时间查询:");
    int flag;
    scanf("%d", &flag);
    if (flag == 1)
    {
        int flag2 = 1;
        pr = student->next;
        printf("请输入学号：");
        scanf("%s", xuehao);
        while (pr != NULL) 
        {
            if (strcmp(pr->data.xuehao, xuehao) == 0)
            {
                flag2 = 0;
                printf("学号：%s  ", pr->data.xuehao);
                printf("姓名：%s  ", pr->data.name);
                printf("时间：%s  到课状态：%s\n", pr->data.data, pr->data.daoke);
            }
            pr = pr->next;
        }
        if (flag2)
        {
            printf("学号不存在！\n");
        }
    }
    else if (flag == 2) //按姓名查询
    {
        pr = student->next;
        printf("请输入姓名：");
        scanf("%s", name);
        while (pr != NULL)
        {
            if (strcmp(pr->data.name, name) == 0)
            {
                printf("学号：%s\n", pr->data.xuehao);
                printf("姓名：%s\n", pr->data.name);
                printf("时间：%s  到课状态：%s", pr->data.data, pr->data.daoke);
            }
            pr = pr->next;
        }
        if (pr == NULL)
        {
            printf("姓名不存在！\n");
        }
    }
    else if(flag==3)  //按时间查询
    {
        pr = student->next;
        printf("(注意！请严格按照00月00日00点00分输入)请输入具体时间：");
        scanf("%s", data);
        while (pr != NULL)
        {
            if (strcmp(pr->data.data, data) == 0) 
            {
                printf("学号：%s\n", pr->data.xuehao);
                printf("姓名：%s\n", pr->data.name);
                printf("时间：%s  到课状态：%s", pr->data.data, pr->data.daoke);
            }
            pr = pr->next;
        }
        if (pr == NULL)
        {
            printf("该时间不存在记录！\n");
        }
    }
}

void add(node* L) 
{
    printf("请输入你想新增信息的学生学号:");
    scanf("%s",xuehao);
    printf("请输入你想新增信息的学生姓名：");
    scanf("%s", name);
    printf("(注意！请严格按照00月00日00点00分输入)请输入到课时间：");
    scanf("%s", data);
    printf("请输入学生班级：");
    scanf("%s", banji);
    node* pr = L->next;
    while (pr != NULL)
    {
        if (strcmp(pr->data.xuehao, xuehao)==0)
        {
            if (strcmp(pr->data.data, data) == 0) 
            {
                printf("该学生在该时间的考勤信息已存在！！");
                break;
            }
        }
        pr = pr->next;
    }
    if (pr == NULL) 
    {
        node* p;
        creatnewnode(p);
        strcpy(p->data.xuehao, xuehao);
        strcpy(p->data.name, name);
        strcpy(p->data.data, data);
        strcpy(p->data.banji, banji);
        printf("注意1为到课  2为旷课  3为事假  4为病假  5为迟到  6为早退\n");
        printf("请输入该时间的到课情况：");
        scanf("%s", daoke);
        strcpy(p->data.daoke,daoke);
        int flag = 1, flag2 = 1, flag3 = 1;
        for (int i = 0; i <= sum1; i++)
        {
            if (strcmp(num[i], xuehao) == 0)
            {
                flag = 0;
            }
        }
        if (flag)
        {
            strcpy(num[sum1], xuehao);
            sum1++;
        }
        for (int i = 0; i <= sum2; i++)
        {
            if (strcmp(num2[i], name) == 0)
            {
                flag2 = 0;
            }
        }
        if (flag2)
        {
            strcpy(num2[sum2], name);
            sum2++;
        }
        for (int i = 0; i <= sum3; i++)
        {
            if (strcmp(num3[i], data) == 0)
            {
                flag3 = 0;
            }
        }
        if (flag3)
        {
            strcpy(num3[sum3], data);
            sum3++;
        }
        insert(L, p);
        printf("添加成功！\n");
    }
}

void modify(node* L)
{
    node* pr = L->next;
    printf("请输入你想要修改的学生学号：");
    scanf("%s", xuehao);
    printf("请输入你想修改学生记录的具体时间：");
    scanf("%s", data);
    while (pr != NULL)
    {
        if(strcmp(pr->data.xuehao, xuehao) == 0)
        {
            if (strcmp(pr->data.data, data) == 0)
            {
                printf("注意1为到课  2为旷课  3为事假  4为病假  5为迟到  6为早退\n");
                printf("请输入学生到课情况：");
                scanf("%s", daoke);
                strcpy(pr->data.daoke, daoke);
                printf("修改成功！\n");
                break;
            }
        }
        pr = pr->next;
    }
    if (pr == NULL)
    {
        printf("无该日学生信息!");
    }
}

void del(node* L)
{
    node* pr = L->next;
    node* p = L;
    if (L->next == NULL)
    {
        printf("无考勤信息，请先添加");
        return;
    }
    printf("请输入你想要删除的学生记录的学生学号：");
    scanf("%s", xuehao);
    printf("请输入你想要删除的学生记录的具体时间：");
    scanf("%s", data);
    int flag = 1;
    while (pr != NULL)
    {
        if (strcmp(pr->data.xuehao, xuehao) == 0)
        {
            if (strcmp(pr->data.data, data) == 0)
            {
                flag = 0;
                p->next = pr->next;
                free(pr);
                node* p = L->next;
                int t = 0, k = 0;
                while (p != NULL)
                {
                    if (strcmp(p->data.xuehao, xuehao) == 0)
                    {
                        t++;
                    }
                    if (strcmp(p->data.data, data) == 0)
                    {
                        k++;
                    }
                    p = p->next;
                }
                if (t == 1)
                {
                    for (int i = 0; i < sum1; i++)
                    {
                        strcpy(num[i] , num[i + 1]);
                    }
                    for (int i = 0; i < sum2; i++)
                    {
                        strcpy(num2[i], num2[i + 1]);
                    }
                    sum1--;
                    sum2--;
                }
                if (k == 1)
                {
                    for (int i = 0; i < sum3; i++)
                    {
                        strcpy(num3[i], num3[i + 1]);
                    }
                    sum3--;
                }
                printf("删除成功\n");
                break;
            }
        }
        p = pr;
        pr = pr->next;
    }
    if (flag)
    {
        printf("该学生记录不存在！\n");
    }
}

void show(node* L)
{
    if (L->next== NULL)
    {
        printf("无学生信息，请先添加\n");
        return;
    }
    else
    {
        printf("注意1为到课  2为旷课  3为事假  4为病假  5为迟到  6为早退\n");
        node* pr = L->next;
        while (pr != NULL)
        {
            printf("学生学号:%s  ", pr->data.xuehao);
            printf("学生姓名:%s  ", pr->data.name);
            printf("学生班级:%s  ", pr->data.banji);
            printf("日期:%s  ", pr->data.data);
            printf("学生到课情况:%s\n", pr->data.daoke);
            pr = pr->next;
        }
    }
}

void paixv(node* L)
{
    node* pr = L->next;
    if (pr == NULL)
    {
        printf("库中无数据");
        return;
    }
    else 
    {
        printf("输入1按学号排序，输入2按姓名排序，输入3按日期排序");
        int flag;
        scanf("%d", &flag);
        if (flag == 1)
        {
            char temp[1000];
            for (int i = 0; i < sum1 - 1; i++)
            {
                for (int j = 0; j < sum1 - i - 1; j++)
                {
                    if (strcmp(num[j], num[j + 1]) > 0)
                    {
                        strcpy(temp, num[j]);
                        strcpy(num[j], num[j + 1]);
                        strcpy(num[j + 1], temp);
                    }
                }
            }
            for (int i = 0; i < sum1; i++)
            {
                node* pr2 = pr;
                while (pr2 != NULL)
                {
                    if (strcmp(pr2->data.xuehao, num[i]) == 0) 
                    {
                        printf("学生学号:%s  ", pr2->data.xuehao);
                        printf("学生姓名:%s  ", pr2->data.name);
                        printf("学生班级:%s  ", pr2->data.banji);
                        printf("日期:%s  ", pr2->data.data);
                        printf("学生到课情况:%s\n", pr2->data.daoke);
                    }
                    pr2 = pr2->next;
                }
            }
        }
        else if (flag == 2)
        {
            char temp[1000];
            for (int i = 0; i < sum2 -1; i++)
            {
                for (int j = 0; j < sum2-i-1; j++)
                {
                    if (strcmp(num2[j], num2[j+1]) > 0)
                    {
                        strcpy(temp, num2[j]);
                        strcpy(num2[j], num2[j + 1]);
                        strcpy(num2[j + 1], temp);
                    }
                }
            }
            for (int i = 0; i < sum2; i++)
            {
                node* pr2 = pr;
                while (pr2 != NULL)
                {
                    if (strcmp(pr2->data.name, num2[i]) == 0)
                    {
                        printf("学生学号:%s  ", pr2->data.xuehao);
                        printf("学生姓名:%s  ", pr2->data.name);
                        printf("学生班级:%s  ", pr2->data.banji);
                        printf("日期:%s  ", pr2->data.data);
                        printf("学生到课情况:%s\n", pr2->data.daoke);
                    }
                    pr2 = pr2->next;
                }
            }
        }
        else if (flag == 3)
        {
            char temp[1000];
            for (int i = 0; i < sum3-1 ; i++)
            {
                for (int j =0; j < sum3-i-1; j++)
                {
                    int x = (num3[j][0] - '0') * 10+(num3[j][1]-'0');
                    int y = (num3[j+1][0] - '0') * 10 + (num3[j+1][1] - '0');
                    int z = (num3[j][4] - '0') * 10 + (num3[j][5] - '0');
                    int k = (num3[j+1][4] - '0') * 10 + (num3[j+1][5] - '0');
                    if (x>y)
                    {
                        strcpy(temp, num3[j]);
                        strcpy(num3[j], num3[j+1]);
                        strcpy(num3[j+1], temp);
                    }
                    else if (x == y)
                    {
                        if (z > k)
                        {
                            strcpy(temp, num3[j]);
                            strcpy(num3[j], num3[j+1]);
                            strcpy(num3[j+1], temp);
                        }
                    }
                }
            }
            for (int i = 0; i < sum3; i++)
            {
                node* pr2 = pr;
                while (pr2 != NULL)
                {
                    if (strcmp(pr2->data.data, num3[i]) == 0)
                    {
                        printf("学生学号:%s  ", pr2->data.xuehao);
                        printf("学生姓名:%s  ", pr2->data.name);
                        printf("学生班级:%s  ", pr2->data.banji);
                        printf("日期:%s  ", pr2->data.data);
                        printf("学生到课情况:%s\n", pr2->data.daoke);
                    }
                    pr2 = pr2->next;
                }
            }
        }

    }
}

void tongji(node* L)
{
    node* pr = L->next;
    int flag;
    printf("请输入数字查看统计报表 1 考勤日报表 2 考勤汇总表 3 考勤异常表 4 请假汇总表:");
    scanf("%d", &flag);
    if (flag == 1)
    {
        for (int i = 0; i < sum3; i++)
        {
            int k = 0;
            printf("%s\t", num3[i]);
            node* p = pr;
            int sum4 = 0, sum5 = 0, sum6 = 0, sum7 = 0,sum8=0,sum9=0;
            while (p != NULL)
            {
                if (strcmp(p->data.data, num3[i]) == 0)
                {
                    if (strcmp(p->data.daoke, "1") == 0)
                    {
                        sum4++;
                    }
                    else if (strcmp(p->data.daoke, "2") == 0)
                    {
                        sum5++;
                    }
                    else if (strcmp(p->data.daoke, "3") == 0)
                    {
                        sum6++;
                    }
                    else if (strcmp(p->data.daoke, "4") == 0)
                    {
                        sum7++;
                    }
                    else if (strcmp(p->data.daoke, "5") == 0)


                    {
                        sum8++;
                    }
                    else if (strcmp(p->data.daoke, "6") == 0)
                    {
                        sum9++;
                    }
                    printf("%s\t", p->data.name);
                    k++;
                }
                p = p->next;
            }
            printf("当日总考勤人数:%d人 出勤%d人 旷课%d人 事假%d人  病假%d人  迟到%d人  早退%d人\n", k,sum4,sum5,sum6,sum7,sum8,sum9);
        }
    }
    else if (flag == 2)
    {
        for (int i = 0; i < sum1; i++)
        {
            int k = 0;
            printf("%s\t", num[i]);
            node* p = pr;
            int sum4 = 0, sum5 = 0, sum6 = 0, sum7 = 0, sum8 = 0, sum9 = 0;
            while (p != NULL)
            {
                if (strcmp(p->data.xuehao, num[i]) == 0)
                {
                    if (strcmp(p->data.daoke, "1") == 0)
                    {
                        sum4++;
                    }
                    else if (strcmp(p->data.daoke, "2") == 0)
                    {
                        sum5++;
                    }
                    else if (strcmp(p->data.daoke, "3") == 0)
                    {
                        sum6++;
                    }
                    else if (strcmp(p->data.daoke, "4") == 0)
                    {
                        sum7++;
                    }
                    else if (strcmp(p->data.daoke, "5") == 0)
                    {
                        sum8++;
                    }
                    else if (strcmp(p->data.daoke, "6") == 0)
                    {
                        sum9++;
                    }
                    printf("%s\t", p->data.name);
                    k++;
                }
                p = p->next;
            }
    
            printf("该学生总上课次数%d 出勤%d次 旷课%d次 事假%d次  病假%d次  迟到%d次  早退%d次\n", k, sum4, sum5, sum6, sum7, sum8, sum9);
        }
    }
    else if (flag == 3)
    {
        printf("注意2为旷课  3为事假  4为病假  5为迟到  6为早退\n");
        node* p = pr;
        while (p != NULL)
        {
            if (strcmp(p->data.daoke, "1") != 0)
            {
                printf("%s   %s   %s   %s    到课情况：%s\n", p->data.xuehao, p->data.name, p->data.banji, p->data.data, p->data.daoke);
            }
            p = p->next;
        }
    }
    else if (flag == 4)
    {
        printf("3为事假  4为病假  \n");
        node* p = pr;
        while (p != NULL)
        {
            if (strcmp(p->data.daoke, "3") == 0|| strcmp(p->data.daoke, "4") == 0)
            {
                printf("%s   %s   %s   %s    到课情况：%s\n", p->data.xuehao, p->data.name, p->data.banji, p->data.data, p->data.daoke);
            }
            p = p->next;
        }
    }
    else
    {
        printf("请输入正确的数字\n");
    }
}

void save(node* L)
{
    FILE* fp;
    node* pr = L->next;
    if ((fp = fopen("data.txt", "wb")) == NULL)
    {
        printf("无法打开文件\n");
        exit(0);
    }
    while (pr)
    {
        if(pr->next == NULL)
        {
            fprintf(fp, "%s\n%s\n%s\n%s\n%s", pr->data.xuehao,pr->data.name,pr->data.banji,pr->data.data,pr->data.daoke);
        }
        else
        {
        fprintf(fp, "%s\n%s\n%s\n%s\n%s\n", pr->data.xuehao, pr->data.name, pr->data.banji, pr->data.data, pr->data.daoke);
        }
        pr = pr->next;

    }
    printf("保存成功！\n");
    fclose(fp);
}

#include"Attendance system.h";


void initwindow() 
{
    printf("**************************大学学生考勤签到系统**********\n");
    printf("*-->               请输入数字实现功能                  *\n");
    printf("*-->              1 新增学生信息数据                   *\n");
    printf("*-->                  2 查找数据                       *\n");
    printf("*-->               3 修改学生记录                      *\n");
    printf("*-->               4 删除学生记录                      *\n");
    printf("*-->             5 显示学生考勤数据列表                *\n");
    printf("*-->                    6 排序                         *\n");
    printf("*-->                  7 数据统计                       *\n");
    printf("*-->                    8 保存                         *\n");
    printf("*-->                    9 退出                         *\n");
    printf("*******************要老实上课嗷~************************\n");
    printf("请在此输入你想要进行操作前的数字：");
}

int main()
{
    node* stude;
    creatnewnode(stude);
    read(stude);
    int flag = 1;
    while (flag)//循环页面操作
    {
        initwindow();
        int n;
        scanf("%d", &n);
        switch (n)
        {
        case 1: 
            add(stude);
            printf("请输入按下回车返回主菜单");
            getchar();
            getchar();
            system("cls");
            break;
        case 2: 
            search(stude);
            printf("请输入按下回车返回主菜单");
            getchar();
            getchar();
            system("cls");
            break;
            modify(stude);
            printf("请输入按下回车返回主菜单");
            getchar();
            getchar();
            system("cls");
            break;
        case 4: 
            del(stude);
            printf("请输入按下回车返回主菜单");
            getchar();
            getchar();
            system("cls");
            break;
        case 5: 
            show(stude);
            printf("请输入按下回车返回主菜单");
            getchar();
            getchar();
            system("cls");
            break;
        case 6:
            paixv(stude);
            printf("请输入按下回车返回主菜单");
            getchar();
            getchar();
            system("cls");
            break;
        case 7:
            tongji(stude);
            printf("请输入按下回车返回主菜单");
            getchar();
            getchar();
            system("cls");
            break;
        case 8:
            save(stude);
            printf("请输入按下回车返回主菜单");
            getchar();
            getchar();
            system("cls");
            break;
        case 9:
            printf("感谢使用本系统！\n");
            flag = 0;
            break;
        default:
            printf("请输入正确的操作数！！！\n");
            break;
        }
    }
    return 0;
}

#undef UNICODE
#undef _UNICODE
#include<stdio.h>
#include<math.h>
#include<string.h>
#include<stdlib.h>
#include<malloc.h>

typedef struct s
{
    char xuehao[100];//学号
    char name[100];//姓名
    char banji[100];//班级
    char data[100];//日期
    char daoke[100];//到课情况
}stud;
typedef struct node
{
    stud data;
    struct node* next;
}node;
void creatnewnode(node*& student);
void insert(node*& L, node* p);
void read(node* L);
void search(node* student);
void add(node* L);
void modify(node* L);
void del(node* L);
void show(node* L);
void paixv(node* L);
void tongji(node* L);
void save(node* L);

Answer 1

比起修改，我甚至更愿意重写一个。
下面是我重写的代码，那个统计函数还没有写，等明天吧。

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

const char*membername[] = {"学号", "姓名", "时间"};

const char *menu =    "**************************大学学生考勤签到系统**********\n"
                    "*-->               请输入数字实现功能                  *\n"
                    "*-->              1 新增学生信息数据                   *\n"
                    "*-->                  2 查找数据                       *\n"
                    "*-->               3 修改学生记录                      *\n"
                    "*-->               4 删除学生记录                      *\n"
                    "*-->             5 显示学生考勤数据列表                *\n"
                    "*-->                    6 排序                         *\n"
                    "*-->                  7 数据统计                       *\n"
                    "*-->                    8 保存                         *\n"
                    "*-->                    9 退出                         *\n"
                    "*******************要老实上课嗷~************************\n"
                    "请在此输入你想要进行操作前的数字：";

template<typename listname>
listname* next_n(listname*p, int n) {//相当于数组的p[n]
    while (p && n--) {
        p = p->next;
    }
    return p;
}

#include<stdio.h>

//将计日起点定为1970年1月1日
#define ORIGIN_YEAR 1600
#define OFFSET_DAYS 135141
#define int_64 long long int

namespace myio {
    char c;
    bool fgetint(FILE*fp, int &num) {//会多吃右端一个字符，建议用空格、回车等分隔
        num = 0;
        while (c = fgetc(fp), c != EOF && (c < '0' || c > '9'));
        if (c == EOF)return false;
        do {
            num *= 10;
            num += c - '0';
            c = fgetc(fp);
        } while (c >= '0' && c <= '9');
        return true;
    }
}

class MyTime {
        int_64 seconds;
        static const int timemaxlength = 64;
        static char MyTimestr[timemaxlength];
        static int days, Year, Month, Day, Hour, Minute, Second;
    public:
        MyTime() {}
        ~MyTime() {};
        MyTime(int_64 seconds);
        MyTime(int days, int seconds);
        MyTime(int year, int month, int day, int hour, int minute, int second);
        void settime(int year, int month, int day, int hour = 0, int minute = 0, int second = 0);
        void gettime(int*year, int*month, int*day, int*hour, int*minute, int*second);
        int getdays();
        int_64 getseconds();
        void output(FILE *fp=stdout, const char *format = "%d年%d月%d日%d时%d分%d秒");
        void input(FILE *fp=stdin, const char *format = NULL); //无格式，强制输入六个数字，跳过一切非数字
        //加减
        MyTime operator + (int_64 seconds);
        MyTime operator - (int_64 seconds);
        int_64 operator - (MyTime&MyTime);
        //自增自减
        MyTime& operator ++();//前置
        MyTime operator ++(int);//后置
        MyTime& operator --();//前置
        MyTime operator --(int);//后置
        //赋值
        MyTime& operator = (int_64 seconds);
        MyTime& operator = (MyTime&time);
        MyTime& operator += (int_64 seconds);
        MyTime& operator -= (int_64 seconds);
        //比较
        bool operator < (MyTime&time);
        bool operator > (MyTime&time);
        bool operator ==(MyTime&time);
        bool operator <=(MyTime&time);
        bool operator >=(MyTime&time);
};

//两个升序链表合并
template<typename listname>
void lmerge(listname *&h, listname *&t, listname *h1, listname *e1, listname *h2, listname *e2, int (*cmp)(listname*, listname*)) {
    listname h3, *p, *q;
    t = &h3;
    for (p = h1, q = h2; p != e1 && q != e2;) {
        if (cmp(p, q) <= 0) {
            t->next = p, t = p, p = p->next;
        } else {
            t->next = q, t = q, q = q->next;
        }
    }
    while (p != e1) t->next = p, t = p, p = p->next;
    while (q != e2) t->next = q, t = q, q = q->next;
    t->next = NULL;
    h = h3.next;
}

//链表归并排序
template<typename listname>
void lmergesort(listname **head, int (*cmp)(listname*, listname*)) {
    listname *t, *l, *m, *r, hh;
    int w;
    for (w = 1; next_n(*head, w); w <<= 1) {
        t = &hh;
        for (l = *head; l; l = r) {
            m = next_n(l, w);
            r = next_n(m, w);
            if (!m)
                while (l)t->next = l, t = l, l = l->next;
            else
                lmerge(t->next, t, l, m, m, r, cmp);
        }
        *head = hh.next;
        //t->next = NULL;
    }
}

//链表查找
template<typename listname>
listname* search(listname *head, listname*tail, listname* p, int (*cmp)(listname*, listname*)) {
    listname *q = head;
    while (q != tail) {
        if (cmp(p, q) == 0) {
            break;
        }
        q = q->next;
    }
    return q;
}

typedef struct Node {
    char xuehao[100];//学号
    char name[100];//姓名
    char banji[100];//班级
    MyTime time;//日期
    int daoke;//到课情况
    struct Node* next;
} node;

int compare_byxuehao(node*p, node*q) {
    return strcmp(p->xuehao, q->xuehao);
}

int compare_byname(node*p, node*q) {
    return strcmp(p->name, q->name);
}

int compare_bybanji(node*p, node*q) {
    return strcmp(p->banji, q->banji);
}

int compare_bytime(node*p, node*q) {
    return p->time - q->time;
}

int compare_bydaoke(node*p, node*q) {
    return p->daoke - q->daoke;
}

int allsame(node *p, node *q) {
    return compare_byxuehao(p, q) || compare_byname(p, q) || compare_bytime(p, q);
}

int (*stu_cmp[6])(node*, node*) = {allsame, compare_byxuehao, compare_byname, compare_bytime, compare_bybanji, compare_bydaoke};

void read(node* L);
void search(node* L);
void add(node* L);
void output(node*p, FILE*fp = stdout);
void modify(node* L);
void del(node* L);
void show(node* L, FILE*fp = stdout);
void paixv(node* L);
void tongji(node* L);
void save(node* L);
void erase(node* L);

int main() {
    node stude;
    read(&stude);
    while (1) {
        int n;
        system("cls");
        printf(menu);
        fflush(stdin);
        scanf("%d", &n);
        switch (n) {
            case 1:
                add(&stude);
                break;
            case 2:
                search(&stude);
                break;
            case 3:
                modify(&stude);
                break;
            case 4:
                del(&stude);
                break;
            case 5:
                show(&stude);
                break;
            case 6:
                paixv(&stude);
                break;
            case 7:
                //tongji(&stude);
                break;
            case 8:
                save(&stude);
                break;
            case 9:
                erase(&stude);
                printf("感谢使用本系统！\n");
                return 0;
            default:
                system("cls");
                printf("请输入正确的操作数！！！\n");
                break;
        }
        printf("请输入按下回车返回主菜单");
        fflush(stdin);
        getchar();
    }
    return 0;
}

void read(node*L) {
    node* t = L;
    FILE* FP;
    FP = fopen("data.txt", "rb");
    if (FP == NULL) {
        printf("This file don't exist!");
        L->next = NULL;
        return;//退出函数
    }
    while (!feof(FP)) {
        t->next = (node*)malloc(sizeof(node));//创建节点中转信息
        if(fscanf(FP, "%s%s%s", t->next->xuehao, t->next->name, t->next->banji)<3){
            free(t->next);
            break;
        }
        t->next->time.input(FP);
        fscanf(FP, "%d", &t->next->daoke);
        //如果需要，在这里可以用条件判断是否free掉
        t = t->next;
    }
    t->next = NULL;
    fclose(FP);
}

void add(node*l) {
    node*t = l, *p;
    while (t->next)t = t->next;
    t->next = (node*)malloc(sizeof(node));
    printf("请输入你想新增信息的学生学号:");
    scanf("%s", t->next->xuehao);
    printf("请输入你想新增信息的学生姓名：");
    scanf("%s", t->next->name);
    printf("请输入到课时间(格式示例: 2001/1/1, 00:00:00)：");
    t->next->time.input(stdin);
    printf("请输入学生班级：");
    scanf("%s", t->next->banji);
    p = l;
    while (p = search(p->next, t->next, t->next, compare_byxuehao), p != t->next) {
        if (p->time == t->next->time) {
            printf("该学生在该时间的考勤信息已存在！！");
            free(t->next);
            t->next = NULL;
            return;
        }
    }
    t = t->next;
    printf("注意1为到课  2为旷课  3为事假  4为病假  5为迟到  6为早退\n");
    printf("请输入该时间的到课情况：");
    scanf("%d", &t->daoke);
    printf("添加成功！\n");
    t->next = NULL;
}

void output(node*p, FILE*fp) {
    if (fp == stdout)fprintf(fp, "学号：");
    fprintf(fp, "%s  ", p->xuehao);
    if (fp == stdout)fprintf(fp, "姓名：");
    fprintf(fp, "%s  ", p->name);
    if (fp == stdout)fprintf(fp, "班级：");
    fprintf(fp, "%s  ", p->banji);
    if (fp == stdout)fprintf(fp, "时间：");
    p->time.output(fp, "%04d/%02d/%02d, %02d:%02d:%02d ");
    if (fp == stdout)fprintf(fp, "到课状态：");
    fprintf(fp, "%d\n", p->daoke);
}

void search(node* L) {
    node p, *q;
    printf("输入1按学号查询，输入2按姓名查询，输入3按考勤时间查询:");
    int flag;
    scanf("%d", &flag);
    if (flag >= 1 && flag <= 3) {
        int flag2 = 1;
        printf("请输入%s：", membername[flag - 1]);
        if(flag==1)scanf("%s", p.xuehao);
        else if(flag==2)scanf("%s", p.name);
        else p.time.input(stdin);
        q = L;
        while (q = search(q->next, (node*)NULL, &p, stu_cmp[flag]), q) {
            flag2 = 0;
            output(q);
        }
        if (flag2) {
            printf("%s不存在！\n", membername[flag - 1]);
        }
    }
}

void modify(node* L) {
    node p, *q;
    printf("请输入你想要修改的学生学号：");
    scanf("%s", p.xuehao);
    printf("请输入你想修改学生记录的具体时间(格式示例: 2001/1/1, 00:00:00)：");
    p.time.input(stdin);
    q = L;
    while (q = search(q->next, (node*)NULL, &p, compare_byxuehao), q) {
        if (q->time == p.time) {
            printf("注意1为到课  2为旷课  3为事假  4为病假  5为迟到  6为早退\n");
            printf("请输入学生到课情况：");
            scanf("%d", &q->daoke);
            printf("修改成功！\n");
            return;
        }
    }
    printf("无该日学生信息!");
}

void del(node* L) {
    node p, *q;
    if (L->next == NULL) {
        printf("无考勤信息，请先添加");
        return;
    }
    printf("请输入你想要删除的学生记录的学生学号：");
    scanf("%s", p.xuehao);
    printf("请输入你想要删除的学生记录的具体时间(格式示例: 2001/1/1, 00:00:00)：");
    p.time.input(stdin);
    q = L;
    for (q = L; q->next; q = q->next) {
        if (q->next->time == p.time && strcmp(q->next->xuehao, p.xuehao)==0) {
            p.next = q->next;
            q->next = q->next->next;
            free(p.next);
            printf("删除成功\n");
            return;
        }
    }
    printf("该学生记录不存在！\n");
}

void show(node *L, FILE*fp) {
    if (L->next == NULL) {
        printf("无学生信息，请先添加\n");
        return;
    }
    if (fp == stdout)printf("注意1为到课  2为旷课  3为事假  4为病假  5为迟到  6为早退\n");
    for (L = L->next; L; L = L->next) {
        output(L, fp);
        fputc('\n', fp);
    }
}

void paixv(node* L) {
    if (L->next == NULL) {
        printf("库中无数据");
        return;
    }
    printf("输入1按学号排序，输入2按姓名排序，输入3按日期排序");
    int flag;
    scanf("%d", &flag);
    if (flag >= 1 && flag <= 3) {
        lmergesort(&L->next, stu_cmp[flag]);
        show(L);
    }
}

void save(node* L) {
    FILE* fp;
    if ((fp = fopen("data.txt", "wb")) == NULL) {
        printf("无法打开文件\n");
        exit(0);
    }
    show(L, fp);
    printf("保存成功！\n");
    fclose(fp);
}

void erase(node* L) {
    node*p;
    for (L = L->next; L; L = p) {
        p = L->next;
        free(L);
    }
}

int MyTime::days, MyTime::Year, MyTime::Month, MyTime::Day, MyTime::Hour, MyTime::Minute, MyTime::Second;

MyTime::MyTime(long long int s) {
    seconds = s;
}

MyTime::MyTime(int d, int s) {
    seconds = (int_64)d * 86400 + s;
}

MyTime::MyTime(int y, int mon, int d, int h, int min, int s) {
    settime(y, mon, d, h, min, s);
}

void MyTime::settime(int year, int month, int day, int hour, int minute, int second) {
    year -= ORIGIN_YEAR;
    seconds =
        month <= 2 ? (
            (year - 1) * 365 + (year - 1) / 4 - (year - 1) / 100 + (year - 1) / 400
            + (month - 1) * 30 + month * 7 / 12
            + day - 1
        ) : (
            (year) * 365 + (year) / 4 - (year) / 100 + (year) / 400
            - (13 - month) * 30 - (14 - month) * 7 / 12
            + day - 1
        );
    seconds -= OFFSET_DAYS;
    seconds = seconds * 86400 + hour * 3600 + minute * 60 + second;
}

void MyTime::gettime(int*year, int*month, int*day, int*hour, int*minute, int*second) {
    days = seconds / 86400;
    Day = days + 306 + OFFSET_DAYS;
    Year = 1;
    Year += Day / 146097 * 400;
    Day %= 146097;
    Year += Day / 36524 * 100;
    Day %= 36524;
    Year += Day / 1461 * 4;
    Day %= 1461;
    Year += Day / 365;
    Day %= 365;
    if (Day < 306) {
        Year--;
    }
    Year += ORIGIN_YEAR;
    Day++;
    Month = (Day * 12 - 8) / 367 + 1;
    Day = Day - ((Month - 1) * 367 + 7) / 12;
    Month = (Month + 1) % 12 + 1;
    Second = seconds % 86400;
    Hour = Second / 3600;
    Second %= 3600;
    Minute = Second / 60;
    Second %= 60;
    if (year)*year = Year;
    if (month)*month = Month;
    if (day)*day = Day;
    if (hour)*hour = Hour;
    if (minute)*minute = Minute;
    if (second)*second = Second;
}

int MyTime::getdays() {
    return seconds / 86400;
}

void MyTime::output(FILE*fp, const char*format) {
    gettime(0, 0, 0, 0, 0, 0);
    fprintf(fp, format, Year, Month, Day, Hour, Minute, Second);
}

void MyTime::input(FILE*fp, const char*format) {
    if (format) {
        fscanf(fp, format, &Year, &Month, &Day, &Hour, &Minute, &Second);
    } else {
        myio::fgetint(fp, Year);
        myio::fgetint(fp, Month);
        myio::fgetint(fp, Day);
        myio::fgetint(fp, Hour);
        myio::fgetint(fp, Minute);
        myio::fgetint(fp, Second);
    }
    settime(Year, Month, Day, Hour, Minute, Second);
}

MyTime MyTime::operator + (int_64 s) {
    return seconds + s;
}

MyTime MyTime::operator - (int_64 s) {
    return seconds - s;
}

int_64 MyTime::operator - (MyTime&time) {
    return seconds - time.seconds;
}

MyTime& MyTime::operator = (int_64 s) {
    seconds = s;
    return *this;
}

MyTime& MyTime::operator = (MyTime&time) {
    seconds = time.seconds;
    return *this;
}

MyTime& MyTime::operator += (int_64 s) {
    seconds += s;
    return *this;
}

MyTime& MyTime::operator -= (int_64 s) {
    seconds -= s;
    return *this;
}

MyTime& MyTime::operator ++() {
    ++seconds;
    return *this;
}

MyTime MyTime::operator ++(int) {
    return seconds++;
}

MyTime& MyTime::operator --() {
    --seconds;
    return *this;
}

MyTime MyTime::operator --(int) {
    return seconds--;
}

bool MyTime::operator < (MyTime&time) {
    return seconds < time.seconds;
}

bool MyTime::operator > (MyTime&time) {
    return seconds > time.seconds;
}

bool MyTime::operator ==(MyTime&time) {
    return seconds == time.seconds;
}

bool MyTime::operator <=(MyTime&time) {
    return seconds <= time.seconds;
}

bool MyTime::operator >=(MyTime&time) {
    return seconds >= time.seconds;
}