C语言用指针编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示例代码，使用了指针来操作学生信息：

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

#define MAX_STUDENTS 100

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

void add_student(Student *students, int *num_students);
void print_students(Student *students, int num_students);
void search_student(Student *students, int num_students);
void delete_student(Student *students, int *num_students);

int main() {
    Student students[MAX_STUDENTS];
    int num_students = 0;
    int option;

    do {
        printf("\n");
        printf("1. Add student\n");
        printf("2. Print students\n");
        printf("3. Search student\n");
        printf("4. Delete student\n");
        printf("5. Exit\n");
        printf("Enter option: ");
        scanf("%d", &option);

        switch (option) {
            case 1:
                add_student(students, &num_students);
                break;
            case 2:
                print_students(students, num_students);
                break;
            case 3:
                search_student(students, num_students);
                break;
            case 4:
                delete_student(students, &num_students);
                break;
            case 5:
                printf("Goodbye!\n");
                break;
            default:
                printf("Invalid option!\n");
                break;
        }
    } while (option != 5);

    return 0;
}

void add_student(Student *students, int *num_students) {
    if (*num_students == MAX_STUDENTS) {
        printf("Maximum number of students reached!\n");
        return;
    }

    Student new_student;
    printf("Enter student name: ");
    scanf("%s", new_student.name);
    printf("Enter student ID: ");
    scanf("%d", &new_student.id);
    printf("Enter student score: ");
    scanf("%f", &new_student.score);

    students[*num_students] = new_student;
    (*num_students)++;

    printf("Student added!\n");
}

void print_students(Student *students, int num_students) {
    if (num_students == 0) {
        printf("No students found!\n");
        return;
    }

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

void search_student(Student *students, int num_students) {
    if (num_students == 0) {
        printf("No students found!\n");
        return;
    }

    int search_id;
    printf("Enter student ID: ");
    scanf("%d", &search_id);

    for (int i = 0; i < num_students; i++) {
        if (students[i].id == search_id) {
            printf("Name: %s\n", students[i].name);
            printf("Score: %.2f\n", students[i].score);
            return;
        }
    }

    printf("Student not found!\n");
}

void delete_student(Student *students, int *num_students) {
    if (*num_students == 0) {
        printf("No students found!\n");
        return;
    }

    int delete_id;
    printf("Enter student ID: ");
    scanf("%d", &delete_id);

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

    printf("Student not found!\n");
}

这个学生成绩管理系统可以添加、打印、搜索和删除学生信息。在添加学生时，使用了指针来操作 `num_students` 变量，以便在函数内部修改它的值，并在函数调用结束后保留修改。在搜索和删除学生时，也使用了指针来操作 `num_students` 变量，以便在删除学生时更新它的值。