C语言写一个学生成绩管理系统

好的，下面是一个简单的学生成绩管理系统的C语言代码：

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

#define MAX_STUDENTS 100

typedef struct {
    char name[20];
    int id;
    float grade;
} student;

void add_student(student students[], int* count);
void print_students(student students[], int count);
void search_student(student students[], int count);
void update_grade(student students[], int count);

int main() {
    student students[MAX_STUDENTS];
    int count = 0;
    int choice;

    while (1) {
        printf("\nStudent Grade Management System\n");
        printf("1. Add Student\n");
        printf("2. Print All Students\n");
        printf("3. Search Student\n");
        printf("4. Update Student Grade\n");
        printf("5. Quit\n");
        printf("Enter your choice: ");
        scanf("%d", &choice);

        switch (choice) {
            case 1:
                add_student(students, &count);
                break;
            case 2:
                print_students(students, count);
                break;
            case 3:
                search_student(students, count);
                break;
            case 4:
                update_grade(students, count);
                break;
            case 5:
                return 0;
            default:
                printf("Invalid choice. Please try again.\n");
        }
    }
}

void add_student(student students[], int* count) {
    if (*count >= 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 student grade: ");
    scanf("%f", &s.grade);

    students[*count] = s;
    (*count)++;
}

void print_students(student students[], int count) {
    if (count == 0) {
        printf("No students found.\n");
        return;
    }

    printf("Name\tID\tGrade\n");
    for (int i = 0; i < count; i++) {
        printf("%s\t%d\t%.2f\n", students[i].name, students[i].id, students[i].grade);
    }
}

void search_student(student students[], int count) {
    if (count == 0) {
        printf("No students found.\n");
        return;
    }
    
    int id;
    printf("Enter student ID to search: ");
    scanf("%d", &id);

    for (int i = 0; i < count; i++) {
        if (students[i].id == id) {
            printf("Name: %s\n", students[i].name);
            printf("ID: %d\n", students[i].id);
            printf("Grade: %.2f\n", students[i].grade);
            return;
        }
    }

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

void update_grade(student students[], int count) {
    if (count == 0) {
        printf("No students found.\n");
        return;
    }

    int id;
    printf("Enter student ID to update grade: ");
    scanf("%d", &id);

    for (int i = 0; i < count; i++) {
        if (students[i].id == id) {
            printf("Enter new grade: ");
            scanf("%f", &students[i].grade);
            printf("Grade updated successfully.\n");
            return;
        }
    }

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

这个学生成绩管理系统可以进行添加学生、查看所有学生、搜索指定学生、更新学生成绩和退出程序等操作。每个学生包括姓名、学号和成绩。程序使用了结构体来存储学生信息，并使用了函数来完成各种操作。