C++之学生成绩管理系统

学生成绩管理系统可以用 C 语言来实现。以下是一个简单的学生成绩管理系统的代码示例，包括添加学生信息、添加课程信息、添加学生成绩、计算学生平均分数和输出学生成绩单等功能。

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

#define MAX_STUDENT_NUM 1000
#define MAX_COURSE_NUM 10
#define COURSE_NAME_LEN 20

// 学生信息结构体
typedef struct {
    char name[20];
    int id;
} Student;

// 课程信息结构体
typedef struct {
    char name[COURSE_NAME_LEN];
    int credit;
} Course;

// 学生成绩结构体
typedef struct {
    int student_id;
    int course_id;
    float score;
} Grade;

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

// 课程数组
Course courses[MAX_COURSE_NUM];
int course_count = 0;

// 成绩数组
Grade grades[MAX_STUDENT_NUM * MAX_COURSE_NUM];
int grade_count = 0;

// 添加学生信息
void add_student() {
    if (student_count >= MAX_STUDENT_NUM) {
        printf("Max student number reached!\n");
        return;
    }

    printf("Enter student name: ");
    scanf("%s", students[student_count].name);
    printf("Enter student id: ");
    scanf("%d", &students[student_count].id);

    student_count++;
}

// 添加课程信息
void add_course() {
    if (course_count >= MAX_COURSE_NUM) {
        printf("Max course number reached!\n");
        return;
    }

    printf("Enter course name: ");
    scanf("%s", courses[course_count].name);
    printf("Enter course credit: ");
    scanf("%d", &courses[course_count].credit);

    course_count++;
}

// 添加学生成绩
void add_grade() {
    int student_id, course_id;
    float score;

    printf("Enter student id: ");
    scanf("%d", &student_id);

    printf("Enter course id: ");
    scanf("%d", &course_id);

    if (student_id < 1 || student_id > student_count) {
        printf("Invalid student id!\n");
        return;
    }

    if (course_id < 1 || course_id > course_count) {
        printf("Invalid course id!\n");
        return;
    }

    printf("Enter score: ");
    scanf("%f", &score);

    grades[grade_count].student_id = student_id;
    grades[grade_count].course_id = course_id;
    grades[grade_count].score = score;

    grade_count++;
}

// 计算学生平均分数
float calculate_avg_score(int student_id) {
    float sum = 0;
    int count = 0;

    for (int i = 0; i < grade_count; i++) {
        if (grades[i].student_id == student_id) {
            sum += grades[i].score;
            count++;
        }
    }

    if (count == 0) {
        return 0;
    } else {
        return sum / count;
    }
}

// 输出学生成绩单
void print_grade_report() {
    printf("Student\tCourse\tScore\n");

    for (int i = 0; i < grade_count; i++) {
        printf("%s\t%s\t%.2f\n", students[grades[i].student_id - 1].name, courses[grades[i].course_id - 1].name, grades[i].score);
    }
}

int main() {
    int choice;

    while(1) {
        printf("\nStudent Grade Management System\n");
        printf("1. Add student\n");
        printf("2. Add course\n");
        printf("3. Add grade\n");
        printf("4. Print grade report\n");
        printf("5. Exit\n");
        printf("Enter your choice: ");
        scanf("%d", &choice);

        switch(choice) {
            case 1:
                add_student();
                break;
            case 2:
                add_course();
                break;
            case 3:
                add_grade();
                break;
            case 4:
                print_grade_report();
                break;
            case 5:
                exit(0);
            default:
                printf("Invalid choice!\n");
                break;
        }
    }

    return 0;
}

这段代码使用了结构体来存储学生、课程和成绩信息，并使用数组来存储多个学生、课程和成绩。通过添加、计算和输出等基本操作，实现了一个简单的学生成绩管理系统。