C语言 学生成绩管理系统

任务描述
设计一个学生成绩管理系统，实现对学生成绩的动态管理，实现对学生成绩的输入，显示，删除，查找，插入，最佳，保存，计算，排序等主要功能。
功能要求
1、每一条记录包括一个学生的学号、姓名、3门课成绩、平均成绩。
2、输入功能：可以一次完成若干条记录的输入。
3、显示功能：完成全部学生记录的显示。
4、查找功能：完成按姓名查找学生记录，并显示。
5、排序功能：按学生平均成绩进行排序。
6、插入功能：按平均成绩高低插入一条学生记录
7、删除功能：如果输入错误，可以删除学生记录；
8、退出。

#include<stdio.h>#include<stdlib.h>#include<string.h>#define SIZE_NAME 10#define SIZE_ID 20int Record = 0;typedef struct {    char name[SIZE_NAME];    char id[SIZE_ID];    int a, b, c;    int ava;}pInfo;typedef struct node {    pInfo people;    struct node *next;}linkList;int menu();int create(linkList *head);int display(linkList *head);int search(linkList *head, char *info);int modify(linkList *head, char *pid);int add2(linkList *head, char *pid);int delt(linkList *head, char *info);int compare(int ava1, int ava2);int sort(linkList *head, int boolean);//1升序 0降序 int main(){    linkList head, *p;    char info[SIZE_ID];    int temp, chus, i;    head.next = NULL;    while (1) {        switch (menu()) {        case 1:            create(&head);            break;        case 2:            display(&head);            break;        case 3:            printf("请输入需要查询的学号或姓名: ");            scanf("%s", info);            p = &head;            p = p->next;            for (i = 0; i < search(&head, info); i++) {                p = p->next;            }            printf("搜索到:\n");            printf("\t\t\t\t学生信息\n");            printf("--------------------------------------------------------------------------------\n");            printf("\t\t学号\t\t姓名\t\t\t平均成绩\n");            printf("--------------------------------------------------------------------------------\n");            printf("%20s\t", p->people.id);            printf("%10s\t", p->people.name);            printf("%20d\n", p->people.ava);            break;        case 4:            printf("请输入需要修改的学号: ");            scanf("%s", info);            modify(&head, info);            break;        case 5:            printf("请输入需要添加的学号: ");            scanf("%s", info);            add2(&head, info);            break;        case 6:            printf("请输入需要删除的学号或姓名: ");            scanf("%s", info);            delt(&head, info);            break;        case 7:            printf("请输入1或0:\n\t1:升序\n\t0:降序\n");            scanf("%d", &temp);            sort(&head, temp);            break;        case 8:            exit(0);            break;        default:            printf("输错了，再来一次\n");        }        system("pause");        system("cls");    }    system("pause");    return 0;}int menu(){    int chus;    printf("\t学生信息\n\n");    printf("请输入(1 -- 8):\n");    printf("\t1.创建学生信息\n");    printf("\t2.显示学生信息\n");    printf("\t3.查询学生信息\n");    printf("\t4.修改学生信息\n");    printf("\t5.添加学生信息\n");    printf("\t6.删除学生信息\n");    printf("\t7.排序学生成绩\n");    printf("\t8.退出\n");    scanf("%d", &chus);    return chus;}int create(linkList *head){    linkList *s, *p;    p = head;    printf("请输入学号 姓名 三科成绩,输入end结束\n");    while (1) {        s = (linkList*)malloc(sizeof(linkList));        scanf("%s", s->people.id);        if (!strcmp(s->people.id, "end")) {            return 0;        }        scanf("%s", s->people.name);        scanf("%d", &s->people.a);        scanf("%d", &s->people.b);        scanf("%d", &s->people.c);        s->people.ava = (s->people.a + s->people.b + s->people.c) / 3;        s->next = p->next;        p->next = s;        p = s;        Record++;    }    return 0;}int display(linkList *head){    int i;    linkList *p;    p = head;    p = p->next;    printf("\t\t\t\t学生信息\n");    printf("--------------------------------------------------------------------------------\n");    printf("\t\t学号\t\t姓名\t\t\t平均成绩\n");    printf("--------------------------------------------------------------------------------\n");    for (i = 0; i < Record; i++, p = p->next) {        printf("%20s\t", p->people.id);        printf("%10s\t", p->people.name);        printf("%20d\n", p->people.ava);    }    return 0;}int search(linkList *head, char *info){    int i;    linkList *p;    p = head;    p = p->next;    for (i = 0; i < Record; i++, p = p->next) {        if ((!strcmp(p->people.id, info)) || (!strcmp(info, p->people.name))) {            return i;        }    }    return -1;}int modify(linkList *head, char *pid){    int i;    linkList *p;    p = head;    p = p->next;    for (i = 0; i < search(head, pid); i++) {        p = p->next;    }    printf("请输入新信息:\n");    scanf("%s", p->people.id);    scanf("%s", p->people.name);    scanf("%d", &p->people.a);    scanf("%d", &p->people.b);    scanf("%d", &p->people.c);    p->people.ava = (p->people.a + p->people.b + p->people.c) / 3;    return 0;}int add2(linkList *head, char *pid){    int i;    linkList *p, *s;    p = head;    p = p->next;    s = (linkList*)malloc(sizeof(linkList));    while (p->next != NULL) {        p = p->next;    }    printf("请输入需要添加的姓名和成绩:\n");    strcpy(s->people.id, pid);    scanf("%s", s->people.name);    scanf("%d", &s->people.a);    scanf("%d", &s->people.b);    scanf("%d", &s->people.c);    s->people.ava = (s->people.a + s->people.b + s->people.c) / 3;    if (search(head, s->people.id) == -1) {        s->next = p->next;        p->next = s;        Record++;    }    else {        printf("学号重复了\n");    }    sort(head, 0);    return 0;}int delt(linkList *head, char *info){    int i, n;    linkList *p, *s;    p = head;    n = search(head, info);    if (-1 == n) {        printf("没有找到\n");        return 0;    }    for (i = 0; i < n; i++) {        p = p->next;    }    p->next = p->next->next;    Record--;    return 0;}int compare(int ava1, int ava2){    if (ava1 < ava2) {        return 1;    }    return 0;}int sort(linkList *head, int boolean){    linkList *p, *pre;    pInfo temp;    if (boolean) {        for (p = head->next; p != NULL; p = p->next) {            for (pre = p->next; pre != NULL; pre = pre->next) {                if (0 == compare(p->people.ava, pre->people.ava)) {                    temp = p->people;                    p->people = pre->people;                    pre->people = temp;                }            }        }    }    else {        for (p = head->next; p != NULL; p = p->next) {            for (pre = p->next; pre != NULL; pre = pre->next) {                if (1 == compare(p->people.ava, pre->people.ava)) {                    temp = p->people;                    p->people = pre->people;                    pre->people = temp;                }            }        }    }    return 0;}