只运用数组编写一个学生成绩管理系统，可运用于C-Free5

好的，以下是一个简单的学生成绩管理系统的代码，使用数组来存储学生信息和成绩：

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

#define MAX_SIZE 100

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

void print_menu();
void add_student(struct student students[], int* size);
void delete_student(struct student students[], int* size);
void modify_student(struct student students[], int size);
void print_all_students(struct student students[], int size);
void search_student(struct student students[], int size);

int main() {
    struct student students[MAX_SIZE];
    int size = 0;
    int choice;

    do {
        print_menu();
        scanf("%d", &choice);
        switch (choice) {
        case 1:
            add_student(students, &size);
            break;
        case 2:
            delete_student(students, &size);
            break;
        case 3:
            modify_student(students, size);
            break;
        case 4:
            print_all_students(students, size);
            break;
        case 5:
            search_student(students, size);
            break;
        case 6:
            printf("Exiting program...\n");
            break;
        default:
            printf("Invalid choice. Please try again.\n");
            break;
        }
    } while (choice != 6);

    return 0;
}

void print_menu() {
    printf("\n--- Student Grade Management System Menu ---\n");
    printf("1. Add a new student\n");
    printf("2. Delete a student\n");
    printf("3. Modify a student's information\n");
    printf("4. Print all students' information\n");
    printf("5. Search for a student\n");
    printf("6. Exit program\n");
    printf("Enter your choice: ");
}

void add_student(struct student students[], int* size) {
    if (*size >= MAX_SIZE) {
        printf("The student database is full. Cannot add any more students.\n");
        return;
    }

    printf("Enter the name of the student: ");
    scanf("%s", students[*size].name);
    printf("Enter the ID number of the student: ");
    scanf("%d", &students[*size].id);
    printf("Enter the score of the student: ");
    scanf("%f", &students[*size].score);

    (*size)++;
    printf("Student added successfully.\n");
}

void delete_student(struct student students[], int* size) {
    int id, i, j;
    printf("Enter the ID number of the student you want to delete: ");
    scanf("%d", &id);

    for (i = 0; i < *size; i++) {
        if (students[i].id == id) {
            for (j = i; j < *size - 1; j++) {
                students[j] = students[j + 1];
            }
            (*size)--;
            printf("Student deleted successfully.\n");
            return;
        }
    }
    printf("Student with ID number %d not found.\n", id);
}

void modify_student(struct student students[], int size) {
    int id, i;
    printf("Enter the ID number of the student you want to modify: ");
    scanf("%d", &id);

    for (i = 0; i < size; i++) {
        if (students[i].id == id) {
            printf("Enter the new name for the student: ");
            scanf("%s", students[i].name);
            printf("Enter the new score for the student: ");
            scanf("%f", &students[i].score);
            printf("Student information modified successfully.\n");
            return;
        }
    }
    printf("Student with ID number %d not found.\n", id);
}

void print_all_students(struct student students[], int size) {
    int i;
    if (size == 0) {
        printf("No students in the database.\n");
        return;
    }
    printf("%-20s%-10s%-10s\n", "Name", "ID", "Score");
    for (i = 0; i < size; i++) {
        printf("%-20s%-10d%-10.2f\n", students[i].name, students[i].id, students[i].score);
    }
}

void search_student(struct student students[], int size) {
    int id, i;
    printf("Enter the ID number of the student you want to search for: ");
    scanf("%d", &id);

    for (i = 0; i < size; i++) {
        if (students[i].id == id) {
            printf("%-20s%-10s%-10s\n", "Name", "ID", "Score");
            printf("%-20s%-10d%-10.2f\n", students[i].name, students[i].id, students[i].score);
            return;
        }
    }
    printf("Student with ID number %d not found.\n", id);
}

该程序使用结构体数组来存储学生信息，有以下功能：

1. 添加学生
2. 删除学生
3. 修改学生信息
4. 打印所有学生信息
5. 搜索学生信息
6. 退出程序

在主函数中，使用一个循环不断显示菜单并等待用户输入选择。根据用户的选择，调用相应的函数来执行相应的操作。这些函数的实现都比较简单，使用了数组来存储学生信息和成绩，通过循环来遍历数组找到对应的学生，然后进行操作。注意，由于数组的大小是有限的，因此在添加学生时需要检查数组是否已满。