一次性用c++写出一个学生管理系统

好的，我可以回答这个问题。一个基本的学生管理系统需要包括以下功能：添加学生信息、删除学生信息、修改学生信息、查询学生信息、显示所有学生信息等。以下是一个简单的示例代码：

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

#define MAX_STUDENT_NUM 100

struct Student {
    char name[20];
    int age;
    char gender[10];
    char major[20];
};

struct Student students[MAX_STUDENT_NUM];
int student_num = 0;

void add_student() {
    if (student_num >= MAX_STUDENT_NUM) {
        printf("The student list is full.\n");
        return;
    }
    struct Student new_student;
    printf("Please enter the student's name: ");
    scanf("%s", new_student.name);
    printf("Please enter the student's age: ");
    scanf("%d", &new_student.age);
    printf("Please enter the student's gender: ");
    scanf("%s", new_student.gender);
    printf("Please enter the student's major: ");
    scanf("%s", new_student.major);
    students[student_num++] = new_student;
    printf("The student has been added successfully.\n");
}

void delete_student() {
    if (student_num == 0) {
        printf("The student list is empty.\n");
        return;
    }
    char name[20];
    printf("Please enter the name of the student you want to delete: ");
    scanf("%s", name);
    int index = -1;
    for (int i = 0; i < student_num; i++) {
        if (strcmp(students[i].name, name) == 0) {
            index = i;
            break;
        }
    }
    if (index == -1) {
        printf("The student is not found.\n");
        return;
    }
    for (int i = index; i < student_num - 1; i++) {
        students[i] = students[i + 1];
    }
    student_num--;
    printf("The student has been deleted successfully.\n");
}

void modify_student() {
    if (student_num == 0) {
        printf("The student list is empty.\n");
        return;
    }
    char name[20];
    printf("Please enter the name of the student you want to modify: ");
    scanf("%s", name);
    int index = -1;
    for (int i = 0; i < student_num; i++) {
        if (strcmp(students[i].name, name) == 0) {
            index = i;
            break;
        }
    }
    if (index == -1) {
        printf("The student is not found.\n");
        return;
    }
    printf("Please enter the new age of the student: ");
    scanf("%d", &students[index].age);
    printf("Please enter the new gender of the student: ");
    scanf("%s", students[index].gender);
    printf("Please enter the new major of the student: ");
    scanf("%s", students[index].major);
    printf("The student has been modified successfully.\n");
}

void query_student() {
    if (student_num == 0) {
        printf("The student list is empty.\n");
        return;
    }
    char name[20];
    printf("Please enter the name of the student you want to query: ");
    scanf("%s", name);
    int index = -1;
    for (int i = 0; i < student_num; i++) {
        if (strcmp(students[i].name, name) == 0) {
            index = i;
            break;
        }
    }
    if (index == -1) {
        printf("The student is not found.\n");
        return;
    }
    printf("Name: %s\nAge: %d\nGender: %s\nMajor: %s\n", students[index].name, students[index].age, students[index].gender, students[index].major);
}

void show_all_students() {
    if (student_num == 0) {
        printf("The student list is empty.\n");
        return;
    }
    printf("Name\tAge\tGender\tMajor\n");
    for (int i = 0; i < student_num; i++) {
        printf("%s\t%d\t%s\t%s\n", students[i].name, students[i].age, students[i].gender, students[i].major);
    }
}

int main() {
    while (1) {
        printf("Please select an operation:\n");
        printf("1. Add a student\n");
        printf("2. Delete a student\n");
        printf("3. Modify a student\n");
        printf("4. Query a student\n");
        printf("5. Show all students\n");
        printf("6. Exit\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("Invalid choice.\n");
                break;
        }
    }
    return 0;
}