Studentregistrationmanagementsystem/源.c

#define _CRT_SECURE_NO_WARNINGS
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
typedef struct Student
{
    char id[20];
    char clas[20];
    char name[20];
    double score1;
    double score2;
    double score3;
    double score;
    struct Student* prev;
    struct Student* next;
}student;//
student* head, * tail;
int tot;
void ins(student *t)
{
    t->prev = tail->prev;
    tail->prev->next = t;
    tail->prev = t;
    t->prev = tail;
    tot++;
}
void del(student* u)
{
    student* v = u->next;
    u->next = v->next;
    v->next->prev = u;
    if (v == tail) tail = u;
    free(v);
    tot--;
}

void input()
{
    student *t;
    t = (struct Student*)malloc(sizeof(struct Student));
    printf("Id "); scanf("%s", t->id);
    printf("class "); scanf("%s", t->clas);
    printf("name "); scanf("%s", t->name);
    printf("score1 "); scanf("%lf", &t->score1);
    printf("score2 "); scanf("%lf", &t->score2);
    printf("score3 "); scanf("%lf", &t->score3);
    t->score = t->score1 + t->score2 + t->score3;
    ins(t);
}

void output()
{
    for (student* u = head; u->next != NULL; u = u->next) {
        student* v = u->next;
        printf("%s,%s,%s,%.1lf,%.1lf,%.1lf,%.1lf\n", v->id, v->clas, v->name,
            v->score1, v->score2, v->score3, v->score);
    }
}

void deletl()
{
    char s[10];
    scanf("%s", s);
    student* u;
    for (u = head; u->next != NULL;) {
        student* v = u->next;
        if (strcmp(s, v->id) == 0 || strcmp(s, v->name) == 0) del(u);
        else u = u->next;
    }
    output();
}

void select()
{
    char s[10];
    scanf("%s", s);
    student* u;
    int flag = 0;
    for ( u = head; u->next != NULL; u = u->next) {
        student* v = u->next;
        if (strcmp(s, v->clas) == 0 || strcmp(s, v->id) == 0)
        {
            printf("%s,%s,%s,%.1lf,%.1lf,%.1lf,%.1lf\n", v->id, v->clas, v->name,
                v->score1, v->score2, v->score3, v->score);
            flag++;
        }
    }
    if (flag == 0)
        printf("there is no eligible student\n");
}

void sort(student* st, student* ed)
{
    student t;
    for (student* i = st; i != ed; i++)
        for (student* j = ed - 1; j != i; j--) {
            int x = strcmp(j->clas, (j - 1)->clas);
            if (x < 0 || x == 0 && j->score >(j - 1)->score) {
                t = *j;
                *j = *(j - 1);
                *(j - 1) = t;
            }
        }
}

void order()
{
    student* students = (student*)malloc(sizeof(student) * tot);
    int n = 0;
    while (head->next != NULL) {
        students[n++] = *(head->next);
        del(head);
    }
    sort(students, students + n);
    for (int i = 0; i < n; i++)
        ins((students+i));
    free(students);
    output();
}

int main()
{
    tail = head = (student*)malloc(sizeof(student));
    head->next = NULL;
    head->prev = NULL;
    tail->next = NULL;
    tail->prev = head;
    tot = 0;
    while (1) {
        printf("1.input\n"
            "2.delete\n"
            "3.select\n"
            "4.order\n"
            "5.output\n"
            "6.quit\n"
            "please input your option\n");
        char op[10];
        while (1) {
            scanf("%s", op);
            if (strlen(op) == 1 && op[0] >= '1' && op[0] <= '6') break;
            printf("Wrong input\n");
        }
        if (op[0] == '6') break;
        while (1) {
            if (op[0] == '1') input();
            else if (op[0] == '2') deletl();
            else if (op[0] == '3') select();
            else if (op[0] == '4') order();
            else if(op[0]=='5') output();
            if (op[0] == '4' || op[0] == '5') 
                break;
            printf("continue?\n");
            char buf[10];
            while (1) {
                scanf("%s", buf);
                if (strcmp(buf, "yes") == 0 || strcmp(buf, "no") == 0) break;
                printf("Wrong input\n");
            }
            if (strcmp(buf, "no") == 0) break;
        }
    }
    return 0;
}