c语言设计学生成绩管理系统

学生成绩管理系统是一个常见的C语言课程设计题目，下面是一个简单的实现方法：

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

#define MAX_STUDENT_NUM 100 // 最大学生数
#define MAX_NAME_LEN 20 // 最大姓名长度
#define MAX_COURSE_NUM 5 // 最大课程数

// 学生结构体
typedef struct {
    char name[MAX_NAME_LEN]; // 姓名
    int id; // 学号
    float scores[MAX_COURSE_NUM]; // 成绩
    float total_score; // 总成绩
    float average_score; // 平均成绩
} Student;

// 学生数组
Student students[MAX_STUDENT_NUM];
int student_num = 0; // 学生数

// 添加学生
void add_student() {
    if (student_num >= MAX_STUDENT_NUM) {
        printf("学生数已达到最大值，无法添加！\n");
        return;
    }
    Student student;
    printf("请输入学生姓名：");
    scanf("%s", student.name);
    printf("请输入学生学号：");
    scanf("%d", &student.id);
    printf("请输入学生各科成绩：\n");
    float total_score = 0;
    for (int i = 0; i < MAX_COURSE_NUM; i++) {
        printf("请输入第%d门课程成绩：", i + 1);
        scanf("%f", &student.scores[i]);
        total_score += student.scores[i];
    }
    student.total_score = total_score;
    student.average_score = total_score / MAX_COURSE_NUM;
    students[student_num++] = student;
    printf("添加成功！\n");
}

// 删除学生
void delete_student() {
    int id;
    printf("请输入要删除的学生学号：");
    scanf("%d", &id);
    int index = -1;
    for (int i = 0; i < student_num; i++) {
        if (students[i].id == id) {
            index = i;
            break;
        }
    }
    if (index == -1) {
        printf("未找到该学生！\n");
        return;
    }
    for (int i = index; i < student_num - 1; i++) {
        students[i] = students[i + 1];
    }
    student_num--;
    printf("删除成功！\n");
}

// 修改学生信息
void modify_student() {
    int id;
    printf("请输入要修改的学生学号：");
    scanf("%d", &id);
    int index = -1;
    for (int i = 0; i < student_num; i++) {
        if (students[i].id == id) {
            index = i;
            break;
        }
    }
    if (index == -1) {
        printf("未找到该学生！\n");
        return;
    }
    printf("请输入学生姓名：");
    scanf("%s", students[index].name);
    printf("请输入学生各科成绩：\n");
    float total_score = 0;
    for (int i = 0; i < MAX_COURSE_NUM; i++) {
        printf("请输入第%d门课程成绩：", i + 1);
        scanf("%f", &students[index].scores[i]);
        total_score += students[index].scores[i];
    }
    students[index].total_score = total_score;
    students[index].average_score = total_score / MAX_COURSE_NUM;
    printf("修改成功！\n");
}

// 查询学生信息
void query_student() {
    int id;
    printf("请输入要查询的学生学号：");
    scanf("%d", &id);
    int index = -1;
    for (int i = 0; i < student_num; i++) {
        if (students[i].id == id) {
            index = i;
            break;
        }
    }
    if (index == -1) {
        printf("未找到该学生！\n");
        return;
    }
    printf("姓名：%s\n", students[index].name);
    printf("学号：%d\n", students[index].id);
    printf("各科成绩：");
    for (int i = 0; i < MAX_COURSE_NUM; i++) {
        printf("%.2f ", students[index].scores[i]);
    }
    printf("\n");
    printf("总成绩：%.2f\n", students[index].total_score);
    printf("平均成绩：%.2f\n", students[index].average_score);
}

// 显示所有学生信息
void show_all_students() {
    printf("学生数：%d\n", student_num);
    printf("姓名\t学号\t各科成绩\t总成绩\t平均成绩\n");
    for (int i = 0; i < student_num; i++) {
        printf("%s\t%d\t", students[i].name, students[i].id);
        for (int j = 0; j < MAX_COURSE_NUM; j++) {
            printf("%.2f\t", students[i].scores[j]);
        }
        printf("%.2f\t%.2f\n", students[i].total_score, students[i].average_score);
    }
}

// 主函数
int main() {
    while (1) {
        printf("请选择操作：\n");
        printf("1.添加学生\n");
        printf("2.删除学生\n");
        printf("3.修改学生信息\n");
        printf("4.查询学生信息\n");
        printf("5.显示所有学生信息\n");
        printf("6.退出\n");
        int choice;
        scanf("%d", &choice);
        switch (choice) {
            case 1:
                add_student();
                break;
            case 2:
                delete_student();
                break;
            case 3:
                modify_student();
                break;
            case 4:
                query_student();
                break;
            case 5:
                show_all_students();
                break;
            case 6:
                exit(0);
            default:
                printf("无效操作！\n");
                break;
        }
    }
    return 0;
}

该程序实现了以下功能：

1. 添加学生信息
2. 删除学生信息
3. 修改学生信息
4. 查询学生信息
5. 显示所有学生信息