學生成績管理系統C（鏈表）語言

#include"stdio.h"
#include"stdlib.h"
#include"string.h"  //用於調用一些函數
struct person {
    char name[20];
    int ID;
    int chinese;
    int english;
    int math;
    struct person *next;   //連接處的指針
};                                 //由於create里面就有initialize所以先把initialize放在前面

void initialize(struct person *p, int num) {  //初始化鏈表里面的值
    printf("innitialize person %d\n name is:", num);  //num用於計入輸入的第幾個同學
    scanf_s("%s", &p->name, sizeof(p->name));
    getchar();
    printf("ID:");
    scanf_s("%d", &p->ID);
    getchar();
    printf("chinese:");
    scanf_s("%d", &p->chinese);
    getchar();
    printf("math:");
    scanf_s("%d", &p->math);
    getchar();
    printf("english:");
    scanf_s("%d", &p->english);
    getchar();
}

struct person *create(int len) {
    int num = 0;
    struct person *h = 0, *c, *pre = 0;
    while (num < len) {
        c = (struct person*)malloc(sizeof(struct person)); //malloc取內存 sizeof為這個內存的大小  然后轉化成指針
        if (num == 0) { h = c; pre = c; }  // 如果num=0  h存下了首地址  為以后拿做准備
        c->next = NULL;
        if (num) {
            pre->next = c;  //pre為前一塊內存的地址  把后一塊的首地址賦給前一塊的尾
            pre = c;      //收尾連接后  pre指前一塊的功能就完成了  然后再指向現在的內存 為下一次拿內存、賦地址做准備
        }
        initialize(c, num);   //每取一塊地址就去輸入一次
        ++num;
    }return h;
}
void traverse(struct person *head) {
    int index = 1;    // 用於計數第幾個學生
    while (head != NULL) {  //同樣一直到后面沒有地址結束
        printf("name is: %s\t ID is:%d\t  chinese is:%d\t  englishi is:%d\t  math is:%d\n", head->name, head->ID, head->chinese, head->english, head->math);
        head = head->next;  //前一個輸完后就要指向下一塊地址
        ++index;
    }
}

int getlength(struct person *head) {
    int num = 0;
    while (head != NULL) {    //當head指向后面沒有了 它就是NULL  結束
        ++num;
        head = head->next;  //如果head 不是NULL ++num后要把head指針指向最后
    }return num;
}

//增加學生信息
void append_node(struct person *h) {
    struct person *t = h, *p;
    while (t->next != NULL) {      
        t = t->next;
    }p = (struct person *)malloc(sizeof(struct person));
    initialize(p, 0);
    p->next = NULL;    
    t->next = p;
    traverse(h);
}


//刪除
struct person * delete_ID(struct person *head, int ID, int len) {
    struct person *t = head;
    struct person *temp;
    for (int i = 0; i < (len - 1); ++i) {
        if (i == 0) {
            if (head->ID == ID) {  head = head->next;  free(t); traverse(head); return head; }
            if ((t->next)->ID == ID) {
                temp = t->next;
                t->next = (t->next)->next;
                free(temp); traverse(head); return head;
            }
        }
        if (i != 0) {
            if ((t->next)->ID == ID) {
                temp = t->next;
                t->next = (t->next)->next;
                free(temp); traverse(head); return head;
            }t = t->next;
        }
    }return head;
}

//學號查詢
void search_ID(struct person *head, int ID) {
    while (head != NULL) {
        if (head->ID == ID) {
            printf("name is: %s\t ID is:%d\t  chinese is:%d\t  englishi is:%d  math is:%d\n", head->name, head->ID, head->chinese, head->english, head->math);
        }head = head->next;
    }
}

//姓名查詢
void search_name(struct person *head, char name[20]) {
    while (head != NULL) {
        if ((strcmp(head->name, name)) == 0) { printf("name is: %s\t ID is:%d\t  chinese is:%d\t  englishi is:%d  math is:%d\n", head->name, head->ID, head->chinese, head->english, head->math); }
        head = head->next;
    }
}

//指定學生修改
void change(struct person *head, char name[20]) {
    while (head != NULL) {
        if (strcmp(head->name, name) == 0) {
            printf(" name is:");
            scanf_s("%s", &head->name, sizeof(head->name));
            getchar();
            printf("ID:");
            scanf_s("%d", &head->ID);
            getchar();
            printf("chinese:");
            scanf_s("%d", &head->chinese);
            getchar();
            printf("english:");
            scanf_s("%d", &head->english);
            getchar();
            printf("math:");
            scanf_s("%d", &head->math);
            getchar();
        }
        head = head->next;
    }
    traverse(head);
}
//數學分數平均數
int average_math(struct person *head, int len) {
    int i = 0, sum = 0, average;
    struct person *t = head;
    while (t != NULL) {
        sum += t->math;
        t = t->next;
    }
    average = (sum / len);
    return average;
}
//英語分數平均數
int average_english(struct person *head, int len) {
    int i = 0, sum = 0, average;
    struct person *t = head;
    while (t != NULL) {
        sum += t->english;
        t = t->next;
    }
    average = (sum / len);
    return average;
}

//語文分數平均數
int average_chinese(struct person *head, int len) {
    int  sum = 0, average;
    struct person *t = head;
    while (t != NULL) {
        sum += t->chinese;
        t = t->next;
    }
    average = (sum / len);
    return average;
}

//成績區間統計
int statistics_math(struct person*head, int min, int max) {
    int conter = 0;
    while (head!= NULL) {
        if (head->math >= min&&head->math <= max) {
            ++conter;
            printf("name:%s math score:%d\n", head->name, head->math);
        }head = head->next;
    }return conter;
}

int statistics_chinese(struct person*head, int min, int max) {
    int conter = 0;
    while (head != NULL) {
        if (head->chinese >= min&&head->chinese <= max) {
            ++conter;
            printf("name:%s chinese score:%d\n", head->name, head->chinese);
        }head = head->next;
    }return conter;
}
int statistics_english(struct person*head, int min, int max) {
    int conter = 0;
    while (head != NULL) {
        if (head->english >= min&&head->english <= max) {
            ++conter;
            printf("name:%s english score:%d\n", head->name, head->english);
        }head = head->next;
    }return conter;
}

//某名學生的平均成績
int average_name(struct person*head, char name[20]) {
    int av = 0;
    while (head != NULL) {
        if (strcmp(head->name, name) == 0) { av += head->math; av += head->chinese; av += head->english; }
        head = head->next;
    }
    av = av / 3;
    return av;
}

//排序數學
void rank_math(struct person *h, int len) {
    struct person  *t = h, *pre = h;
    int i, math, chinese, english,ID;
    char name[20];
    t = t->next;
    for (i = 0; i < (len - 1); ++i) {
        while (t != NULL) {
            if ((t->math) >(pre->math)) {
                ID = t->ID; t->ID = pre->ID; pre->ID = ID;
                math = t->math; t->math = pre->math; pre->math = math;
                strcpy_s(name, t->name); strcpy_s(t->name, pre->name); strcpy_s(pre->name, name);
                chinese = t->chinese; t->chinese = pre->chinese; pre->chinese = chinese;
                english = t->english; t->english = pre->english; pre->english = english;
            }
            t = t->next;
        }pre = pre->next; t = pre->next;
    }
    traverse(h);
}
//排序語文
void rank_chinese(struct person *h, int len) {
    struct person  *t = h, *pre = h;
    int i, math, chinese, english,ID;
    char name[20];
    t = t->next;
    for (i = 0; i < (len - 1); ++i) {
        while (t != NULL) {
            if ((t->chinese) >(pre->chinese)) {
                ID = t->ID; t->ID = pre->ID; pre->ID = ID;
                math = t->math; t->math = pre->math; pre->math = math;
                strcpy_s(name, t->name); strcpy_s(t->name, pre->name); strcpy_s(pre->name, name);
                chinese = t->chinese; t->chinese = pre->chinese; pre->chinese = chinese;
                english = t->english; t->english = pre->english; pre->english = english;
            }
            t = t->next;
        }pre = pre->next; t = pre->next;
    }
    traverse(h);
}

//排序英語
void rank_english(struct person *h, int len) {
    struct person  *t = h, *pre = h;
    int i, math, chinese, english,ID;
    char name[20];
    t = t->next;
    for (i = 0; i < (len - 1); ++i) {
        while (t != NULL) {
            if ((t->english) >(pre->english)) {
                ID = t->ID; t->ID = pre->ID; pre->ID = ID;
                math = t->math; t->math = pre->math; pre->math = math;
                strcpy_s(name, t->name); strcpy_s(t->name, pre->name); strcpy_s(pre->name, name);
                chinese = t->chinese; t->chinese = pre->chinese; pre->chinese = chinese;
                english = t->english; t->english = pre->english; pre->english = english;
            }
            t = t->next;
        }pre = pre->next; t = pre->next;
    }
    traverse(h);
}

void release(struct person *head) {
    struct person *n;   //需要一個指針存着下一個地址
    while (head != NULL) {
        n = head->next;  //把n指向下一塊要釋放的地址
        free(head);
        head = n;   //然后再把head從前一個地址移到下一個地址
    }
}
//取長度
int getlen(struct person *head) {
    int conter = 0;
    struct person*t = head;
    while (t != NULL) {
        ++conter;
        t = t->next;
    }
    return conter;
}
//存入文件
void openfile(struct person *head, int len) {
    FILE *fp;
    struct person*t = head;
    errno_t err;
    int temp;
    char str[100];
    char s[10];
    if ((err = fopen_s(&fp, "D:\\學生信息", "w")) != 0)
    {
        printf("文件打開錯誤\n");
    }
    else
    {
        printf("文件打開成功\n");
    }
    for (int i = 0; i < len; ++i) {
        strcpy_s(str, t->name);
        fputs("name:", fp);
        fputs(str, fp);
        fputs(": ", fp);

        fputs("ID:", fp);
        sprintf_s(s, "%d", t->ID);
        fputs(s, fp);
        fputs("  ", fp);

        sprintf_s(s, "%d", t->chinese);
        fputs("chinese:", fp);
        fputs(s, fp);
        fputs("  ", fp);

        sprintf_s(s, "%d", t->math);
        fputs("math:", fp);
        fputs(s, fp);
        fputs("  ", fp);

        sprintf_s(s, "%d", t->english);
        fputs("english:", fp);
        fputs(s, fp);
        fputs("\n", fp);
        t = t->next;
    }
    return;
}


void menu(struct person *head, int len) {
    int m = 0;
    int min, max;
    int ID = 0;
    int conter = 0;
    char name[20];
    while (1) {
            printf("                      請選擇您需要的操作：\n");
            printf("                                       0.  遍歷學生信息\n");
            printf("                                       1.  增加學生信息\n");
            printf("                                       2.  刪除學生信息\n");
            printf("                                       3.  修改學生信息\n");
            printf("                                       4.  按姓名查詢\n");
            printf("                                       5.  按學號查詢\n");
            printf("                                       6.  語文成績在某個區間段的人數以及學生\n");
            printf("                                       7.  數學成績在某個區間段的人數以及學生\n");
            printf("                                       8.  英語成績在某個區間段的人數以及學生\n");
            printf("                                       9.  語文平均分\n");
            printf("                                       10. 數學平均分\n");
            printf("                                       11. 英語平均分\n");
            printf("                                       12. 某個學生的三科平均成績\n");
            printf("                                       13. 按語文成績從高到低排序\n");
            printf("                                       14. 按數學成績從高到低排序\n");
            printf("                                       15. 按英語成績從高到底排序\n");
            printf("                                       16. 結束功能並把信息寫入文件中\n");
            scanf_s("%d", &m);
            switch (m) {
            case 0: traverse(head); break;
            case 1: append_node(head); break;
            case 2: {printf("要刪除學生信息的學號:");
                scanf_s("%d", &ID);
                head=delete_ID(head, ID, getlen(head)); }break;
            case 3: {printf("需要修改學生信息的同學姓名：");
                scanf_s("%s", &name, sizeof(name));
                change(head, name); }break;
            case 4: {printf("search by name:");
                scanf_s("%s", &name, sizeof(name));
                search_name(head, name); }break;
            case 5: {printf("學號查詢：");
                scanf_s("%d", &ID);
                search_ID(head, ID); }break;
            case 6: {printf("請輸入語文成績的區間:");
                printf("min=");
                scanf_s("%d", &min);
                printf("max=");
                scanf_s("%d", &max);
                printf("語文成績在區間%d到%d之間的學生：%d人\n", min, max, statistics_chinese(head, min, max)); }break;
            case 7: {printf("請輸入數學成績的區間:");
                printf("min=");
                scanf_s("%d", &min);
                printf("max=");
                scanf_s("%d", &max);
                printf("數學成績在區間%d到%d之間的學生:%d人\n", min, max, statistics_math(head, min, max)); }break;
            case 8: {printf("請輸入英語成績的區間:");
                printf("min=");
                scanf_s("%d", &min);
                printf("max=");
                scanf_s("%d", &max);
                printf("英語成績在區間%d到%d之間的學生:共有%d人\n", min, max, statistics_english(head, min, max)); }break;
            case 9: { printf("average of chinese is%d", average_chinese(head, getlen(head))); }break;
            case 10: { printf("average of math is%d", average_math(head, getlen(head))); }break;
            case 11: { printf("average of english is%d", average_english(head, getlen(head))); }break;
            case 12: {printf("請輸入學生的姓名：");
                scanf_s("%s", &name, sizeof(name));
                printf("%s 的平均成績為：%d", name, average_name(head, name)); }break;
            case 13: {printf("按照語文成績從高到底排序：");
                rank_chinese(head, getlen(head)); }break;
            case 14: {printf("按照數學成績從高到底排序：");
                rank_math(head, getlen(head)); }break;
            case 15: {printf("按照英語成績從高到底排序：");
                rank_english(head, getlen(head)); }break;
            case 16: openfile(head, getlen(head)); return;
            }
    }
}

int main() {
    struct person *head;
    int len;
    int min, max;
    int ID = 0;
    char name[20];
    printf("請輸入學生信息");
    printf("學生人數:");
    scanf_s("%d", &len);  //輸入要取的地址多少
    head = create(len);   // 創建地址   在create里面就有初始復制函數嵌套
    traverse(head);    //遍歷
    menu(head, getlen(head));
    release(head);       //釋放內存
    system("pause");
    return 0;
}