学生信息管理系统

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

// 定义学生结构体
struct Student {
    char name[50];
    int age;
    float score;
};

// 添加学生信息
void addStudent(struct Student** students, int* numStudents, struct Student newStudent) {
    (*numStudents)++;
    *students = (struct Student*)realloc(*students, (*numStudents) * sizeof(struct Student));
    (*students)[*numStudents - 1] = newStudent;
}

// 显示所有学生信息
void displayStudents(struct Student* students, int numStudents) {
    for (int i = 0; i < numStudents; i++) {
        printf("Name: %s\n", students[i].name);
        printf("Age: %d\n", students[i].age);
        printf("Score: %.2f\n", students[i].score);
        printf("\n");
    }
}

// 根据姓名查找学生信息
struct Student findStudentByName(struct Student* students, int numStudents, char* name) {
    for (int i = 0; i < numStudents; i++) {
        if (strcmp(students[i].name, name) == 0) {
            return students[i];
        }
    }
    struct Student emptyStudent = {"", 0, 0.0};
    return emptyStudent;
}

int main() {
    struct Student* students = NULL; // 学生信息数组指针
    int numStudents = 0; // 学生数量

    // 添加学生信息示例
    addStudent(&students, &numStudents, {"Alice", 20, 85.5});
    addStudent(&students, &numStudents, {"Bob", 21, 90.0});
    addStudent(&students, &numStudents, {"Charlie", 22, 78.5});

    // 显示所有学生信息
    displayStudents(students, numStudents);

    // 根据姓名查找学生信息示例
    char nameToFind[] = "Bob";
    struct Student foundStudent = findStudentByName(students, numStudents, nameToFind);
    printf("Found student: \n");
    printf("Name: %s\n", foundStudent.name);
    printf("Age: %d\n", foundStudent.age);
    printf("Score: %.2f\n", foundStudent.score);
    printf("\n");

    // 释放内存
    free(students);

    return 0;
}

逐行解释：

1. #include <stdio.h>、#include <stdlib.h>、#include <string.h>：引入标准库头文件，分别用于输入输出、动态内存分配和字符串处理。

2. struct Student {...};：定义了一个名为Student的结构体，包含了学生的姓名、年龄和分数。

3. void addStudent(struct Student** students, int* numStudents, struct Student newStudent) {...}：函数用于向学生数组中添加新的学生信息。

4. void displayStudents(struct Student* students, int numStudents) {...}：函数用于显示所有学生的信息。

5. struct Student findStudentByName(struct Student* students, int numStudents, char* name) {...}：函数用于根据姓名查找学生的信息。

6. int main() {...}：主函数开始。

7. struct Student* students = NULL;、int numStudents = 0;：声明并初始化学生信息的数组指针和学生数量。

8. addStudent(&students, &numStudents, {...});：调用addStudent函数添加了三个学生信息到学生数组中。

9. displayStudents(students, numStudents);：调用displayStudents函数显示所有学生信息。

10. char nameToFind[] = "Bob";：声明一个字符串用于查找学生信息。

11. struct Student foundStudent = findStudentByName(students, numStudents, nameToFind);：调用findStudentByName函数根据姓名查找学生信息。

12. free(students);：释放动态分配的内存空间。