编一个学生信息管理系统，求大神帮忙 - C语言论坛

lf1010849299
等　级：新手上路
帖　子：12
专家分：0
注　册：2016-11-15
结帖率：75%
楼主
已结贴√ 问题点数：20 回复次数：5
编一个学生信息管理系统，求大神帮忙
题目要求：    1、从文件中读入学生相关信息存入链表（创建）；
            2、实现对链表的插入/多关键字删除操作；
            3、实现对链表的多关键字排序操作；
            4、实现对链表的保存（原文件）和另存（新文件）功能；
            5、将功能实现为菜单形式，方便用户进行任意操作序列。
搜索更多相关主题的帖子: 管理系统　关键字　信息　用户　
2017-02-13 10:34
yanzy
等　级：职业侠客
威　望：2
帖　子：104
专家分：372
注　册：2017-2-7
第 3 楼
得分:10
明天写一下
代码来了，很粗糙，特别是排序算法，这两天卡这里了，以后再优化一下
程序代码：
/*
1、从文件中读入学生相关信息存入链表（创建）；
2、实现对链表的插入/多关键字删除操作；
3、实现对链表的多关键字排序操作；
4、实现对链表的保存（原文件）和另存（新文件）功能；
5、将功能实现为菜单形式，方便用户进行任意操作序列。
*/
#include <stdio.h>
#include <time.h>
#include <string.h>
#include <stdbool.h>

struct students {
    char name[20];//学生名字
    int number;//学生学号
    int classes;//班级
    float math;//数学成绩
    float chinese;//语文成绩
    float english;//英语成绩
    struct students *next;
};

struct students *student = NULL;//指向初始位置
bool yesorno = false;

struct students *insert(void);
struct students *find(char *str);
void dele(void);
void sort(void);
void search(void);
void save(void);
void save_as(void);
void read(void);
void quit(void);
void print(void);

int main(void)
{
    char code;

    for (;;)
    {
        printf("请选择您需要的操作\n");
        printf("输入（I），删除（D），排序（X），搜索（S），保存（B），另存（L），读取（R），退出（Q）：\n");

        scanf(" %c", &code);
        while (getchar() != '\n')
            ;
        switch (code)
        {
        case 'i':case 'I':insert(); break;
        case 'd':case 'D':dele(); break;
        case 'x':case 'X':sort(); break;
        case 's':case 'S':search(); break;
        case 'b':case 'B':save(); break;
        case 'L':case 'l':save_as(); break;
        case 'r':case 'R':read(); break;
        case 'q':case 'Q':quit(); break;
        case 'p':case 'P':print(); break;
        default:printf("enter wrong.\n"); break;
        }
    }
}

struct students *find(char *str)
{
    struct students *tmp;
    for (tmp = student; tmp; tmp = tmp->next)
        if ((strcmp(str, tmp->name) == 0) || (strcmp(str, tmp->number) == 0))
            return tmp;
    if (tmp == NULL)
    {
        printf("Not found.\n");
        return NULL;
    }
}

struct students *insert(void)
{
    struct students *tmp = malloc(sizeof(struct students));
    if (tmp == NULL)
    {
        fprintf(stderr, "No momory space.\n");
        return;
    }
    printf("请输入学生所在班级：");
    scanf("%d", &tmp->classes);
    while (getchar() != '\n')
        ;
    printf("请输入学生名字：");
    gets(tmp->name);
    printf("请输入学生学号：");
    scanf("%d", &tmp->number);
    printf("请输入学生数学成绩：");
    scanf("%f", &tmp->math);
    printf("请输入学生语文成绩：");
    scanf("%f", &tmp->chinese);
    printf("请输入学生英语成绩：");
    scanf("%f", &tmp->english);

    tmp->next = student;
    student = tmp;
    yesorno = false;
    return student;
}

void dele(void)
{
    char code[20], ch;
    struct students *tmp, *tmp1;
    printf("请输入您要删除的学生名字或学号：");
    gets(code);
    tmp = find(code);
    if (tmp == NULL)
        return;
    printf("班级：%d\n", tmp->classes);
    printf("名字: ");
    puts(tmp->name);
    printf("学号: %d\n", tmp->number);
    printf("are you sure delete ?(y/n) : ");
    ch = getchar();
    if (ch == 'y' || ch == 'Y')
    {
        if (tmp == student)
            student = student->next;
        else
        {
            for (tmp1 = student; tmp1->next != tmp; tmp1 = tmp1->next)
                ;
            tmp1->next = tmp->next;
        }
        free(tmp);
        printf("delete success.\n");
    }
    yesorno = false;
    return;
}

void print(void)
{
    struct students *tmp;
    printf("Students data:\n");
    printf("classes     name        number      math        chinese     english     \n");
    for (tmp = student; tmp; tmp = tmp->next)
        printf("%-12d%-12s%-12d%-12g%-12g%-12g\n", tmp->classes, tmp->name, tmp->number, tmp->math, tmp->chinese, tmp->english);
    printf("\n\n");
    return;
}

void quit(void)
{
    if (yesorno)
        exit(0);
    else
    {
        printf("尚未保存，是否直接退出？返回（y），退出（n）:");
        char code;
        for (;;)
        {
            scanf(" %c", &code);
            if (code == 'y' || code == 'Y')
                return;
            else if (code == 'n' || code == 'N')
                exit(0);
            else
                printf("Enter wrong,try again: ");
        }
    }
}

void save(void)
{
    FILE *fp;

    if ((fp = fopen("studentsdata.txt", "w")) == NULL)
    {
        fprintf(stderr, "Can't build studentsdata.txt\n");
        exit(0);
    }
    struct students *tmp;
    for (tmp = student; tmp; tmp = tmp->next)
    {
        fprintf(fp,"%d\n%s\n%d\n%.1f\n%.1f\n%.1f\n", tmp->classes, tmp->name, tmp->number, tmp->math, tmp->chinese, tmp->english);
    }
    fclose(fp);
    printf("存储完毕\n");
    yesorno = true;
    return;
}

void save_as(void)
{
    struct students *tmp;
    char str[20];

    printf("请输入保存的文件名：");
    gets(str);
    FILE *fp = fopen(str, "w");
    if (fp == NULL)
    {
        fprintf(stderr, "Can't build %s\n", str);
        exit(0);
    }
    for (tmp = student; tmp; tmp = tmp->next)
    {
        fprintf(fp, "%d\n%s\n%d\n%.1f\n%.1f\n%.1f\n", tmp->classes, tmp->name, tmp->number, tmp->math, tmp->chinese, tmp->english);
    }
    fclose(fp);
    printf("另存储完毕\n");
    yesorno = true;
    return;
}

void read(void)
{
    FILE *fp;

    if ((fp = fopen("studentsdata.txt", "r")) == NULL)
    {
        fprintf(stderr, "Can't open studentsdata.txt\n");
        exit(0);
    }

    for (;!feof(fp);)
    {
        struct students *tmp = malloc(sizeof(struct students));
        if (tmp == NULL)
        {
            fprintf(stderr, "No momory space.\n");
            return;
        }
        fscanf(fp, "%d\n", &tmp->classes);
        fscanf(fp, "%s\n", tmp->name);
        fscanf(fp, "%d\n%f\n%f\n%f\n",  &tmp->number, &tmp->math, &tmp->chinese, &tmp->english);
        tmp->next = student;
        student = tmp;
    }
    fclose(fp);
    printf("读取完成\n");
    yesorno = false;
    return;
}

void search(void)
{
    char code[20];
    struct students *tmp;
    printf("请输入您要查找的学生名字或学号：");
    gets(code);
    tmp = find(code);
    if (tmp != NULL)
    {
        printf("Students data:\n");
        printf("classes     name        number      math        chinese     english     \n");
        printf("%-12d%-12s%-12d%-12.1f%-12.1f%-12.1f\n", tmp->classes, tmp->name, tmp->number, tmp->math, tmp->chinese, tmp->english);
        printf("\n");
    }
    return;
}

void sort(void)//排序算法很粗糙，这是我自己的想出来的，改进也有，比如变成双链表，完成排序后销毁等
{
    char code, code1;
    bool x = true;
    printf("请选择排序关键字：学号（n），数学（m），语文（c）：");//暂定3个，可继续添加
    
    scanf(" %c", &code);
    while (getchar() != '\n')
        ;
    printf("升级排序（u），降级排序（d）：");
    scanf(" %c", &code1);
    while (getchar() != '\n')
        ;
    if (code1 == 'u')
    {
        if (code == 'n')
        {
            struct students *cur, *prev, *tmp;
            for (;;)
            {
                x = true;
                for (cur = student->next, prev = student; cur != NULL; prev = cur, cur = cur->next)
                {
                    if (prev->number > cur->number)
                    {
                        prev->next = cur->next;
                        cur->next = prev;
                        if (prev == student)//保证student指向头
                            student = cur;
                        else {
                            for (tmp = student; tmp->next != prev; tmp = tmp->next)//保证调整位置前后指针连接
                                ;
                            tmp->next = cur;
                        }
                        tmp = cur;
                        cur = prev;
                        prev = tmp;
                        x = false;//只要进行了位置调整，x都为false，以保证继续循环
                    }
                }
                if (x)
                    break;
            }
        }
        if (code == 'm')
        {
            struct students *cur, *prev, *tmp;
            for (;;)
            {
                x = true;
                for (cur = student->next, prev = student; cur != NULL; prev = cur, cur = cur->next)
                {
                    if (prev->math > cur->math)
                    {
                        prev->next = cur->next;
                        cur->next = prev;
                        if (prev == student)
                            student = cur;
                        else {
                            for (tmp = student; tmp->next != prev; tmp = tmp->next)
                                ;
                            tmp->next = cur;
                        }
                        tmp = cur;
                        cur = prev;
                        prev = tmp;
                        x = false;
                    }
                }
                if (x)
                    break;
            }
        }
        if (code == 'c')
        {
            struct students *cur, *prev, *tmp;
            for (;;)
            {
                x = true;
                for (cur = student->next, prev = student; cur != NULL; prev = cur, cur = cur->next)
                {
                    if (prev->chinese > cur->chinese)
                    {
                        prev->next = cur->next;
                        cur->next = prev;
                        if (prev == student)
                            student = cur;
                        else {
                            for (tmp = student; tmp->next != prev; tmp = tmp->next)
                                ;
                            tmp->next = cur;
                        }
                        tmp = cur;
                        cur = prev;
                        prev = tmp;
                        x = false;
                    }
                }
                if (x)
                    break;
            }
        }
    }
    if (code1 == 'd')
    {
        if (code == 'n')
        {
            struct students *cur, *prev, *tmp;
            for (;;)
            {
                x = true;
                for (cur = student->next, prev = student; cur != NULL; prev = cur, cur = cur->next)
                {
                    if (prev->number < cur->number)
                    {
                        prev->next = cur->next;
                        cur->next = prev;
                        if (prev == student)
                            student = cur;
                        else {
                            for (tmp = student; tmp->next != prev; tmp = tmp->next)
                                ;
                            tmp->next = cur;
                        }
                        tmp = cur;
                        cur = prev;
                        prev = tmp;
                        x = false;
                    }
                }
                if (x)
                    break;
            }
        }
        if (code == 'm')
        {
            struct students *cur, *prev, *tmp;
            for (;;)
            {
                x = true;
                for (cur = student->next, prev = student; cur != NULL; prev = cur, cur = cur->next)
                {
                    if (prev->math < cur->math)
                    {
                        prev->next = cur->next;
                        cur->next = prev;
                        if (prev == student)
                            student = cur;
                        else {
                            for (tmp = student; tmp->next != prev; tmp = tmp->next)
                                ;
                            tmp->next = cur;
                        }
                        tmp = cur;
                        cur = prev;
                        prev = tmp;
                        x = false;
                    }
                }
                if (x)
                    break;
            }
        }
        if (code == 'c')
        {
            struct students *cur, *prev, *tmp;
            for (;;)
            {
                x = true;
                for (cur = student->next, prev = student; cur != NULL; prev = cur, cur = cur->next)
                {
                    if (prev->chinese < cur->chinese)
                    {
                        prev->next = cur->next;
                        cur->next = prev;
                        if (prev == student)
                            student = cur;
                        else {
                            for (tmp = student; tmp->next != prev; tmp = tmp->next)
                                ;
                            tmp->next = cur;
                        }
                        tmp = cur;
                        cur = prev;
                        prev = tmp;
                        x = false;
                    }
                }
                if (x)
                    break;
            }
        }
    }
    printf("排序完毕。\n");
    return;
}
[此贴子已经被作者于2017-2-18 00:17编辑过]
2017-02-13 23:44
炎天
来　自：桃花岛
等　级：贵宾
威　望：29
帖　子：1218
专家分：4986
注　册：2016-9-15
第 5 楼
得分:0
void fun(struct student *student)
{
   struct student *p;

   while(student)
   {
      p = student;
      student = student->next;
      free(p)
    }
}
早知做人那么辛苦！当初不应该下凡
2017-02-18 14:22