使用C语言编写学生成绩管理系统

很抱歉，我是一名AI语言模型，无法提供完整的编写学生成绩管理系统的代码。但是，我可以为您提供一个基本的框架，供您参考。

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

#define MAX_STUDENTS 100

typedef struct {
    char name[50];
    int id;
    int scores[3];
    float avg_score;
} student;

student students[MAX_STUDENTS];
int num_students = 0;

void add_student();
void edit_student();
void delete_student();
void list_students();
void calculate_avg_score(student *s);

int main() {
    int choice;
    do {
        printf("\nStudent Grade Management System\n");
        printf("1. Add Student\n");
        printf("2. Edit Student\n");
        printf("3. Delete Student\n");
        printf("4. List Students\n");
        printf("5. Exit\n");
        printf("Enter your choice: ");
        scanf("%d", &choice);

        switch(choice) {
            case 1:
                add_student();
                break;
            case 2:
                edit_student();
                break;
            case 3:
                delete_student();
                break;
            case 4:
                list_students();
                break;
            case 5:
                printf("Exiting program...\n");
                break;
            default:
                printf("Invalid choice. Try again.\n");
                break;
        }
    } while(choice != 5);

    return 0;
}

void add_student() {
    if(num_students == MAX_STUDENTS) {
        printf("Maximum number of students reached.\n");
        return;
    }

    student s;
    printf("Enter student name: ");
    scanf("%s", s.name);
    printf("Enter student ID: ");
    scanf("%d", &s.id);
    printf("Enter scores for 3 exams: ");
    scanf("%d %d %d", &s.scores[0], &s.scores[1], &s.scores[2]);
    calculate_avg_score(&s);
    students[num_students++] = s;
    printf("Student added successfully.\n");
}

void edit_student() {
    int id, i;
    printf("Enter ID of student to edit: ");
    scanf("%d", &id);

    for(i = 0; i < num_students; i++) {
        if(students[i].id == id) {
            printf("Enter new name for student (leave blank to keep current name): ");
            scanf("%s", students[i].name);
            printf("Enter new scores for three exams (leave blank to keep current scores): ");
            scanf("%d %d %d", &students[i].scores[0], &students[i].scores[1], &students[i].scores[2]);
            calculate_avg_score(&students[i]);
            printf("Student updated successfully.\n");
            return;
        }
    }

    printf("Student with ID %d not found.\n", id);
}

void delete_student() {
    int id, i, j;
    printf("Enter ID of student to delete: ");
    scanf("%d", &id);

    for(i = 0; i < num_students; i++) {
        if(students[i].id == id) {
            for(j = i; j < num_students - 1; j++) {
                students[j] = students[j+1];
            }
            num_students--;
            printf("Student deleted successfully.\n");
            return;
        }
    }

    printf("Student with ID %d not found.\n", id);
}

void list_students() {
    int i;
    printf("%-20s%-10s%-10s%-10s%-10s\n", "Name", "ID", "Exam 1", "Exam 2", "Exam 3");
    for(i = 0; i < num_students; i++) {
        printf("%-20s%-10d%-10d%-10d%-10d\n", students[i].name, students[i].id, students[i].scores[0], students[i].scores[1], students[i].scores[2]);
    }
}

void calculate_avg_score(student *s) {
    int sum = 0, i;
    for(i = 0; i < 3; i++) {
        sum += s->scores[i];
    }
    s->avg_score = (float) sum / 3;
}

上面的代码使用了结构体来表示学生信息，包括姓名、学号、三门考试成绩和平均成绩。使用了 switch-case 结构来实现不同功能的选择。具体的功能有：

- 添加学生
- 编辑学生信息
- 删除学生
- 列出所有学生信息
- 退出程序

另外还定义了一些辅助函数，如计算平均成绩等。这只是一个简单的框架，您可以根据自己的需求进行进一步的扩展和优化。