C语言学生信息管理系统，包含统计学生信息功能

好的，一个简单的C语言学生信息管理系统可以包含以下几个功能：

1. 添加学生信息：输入学生的姓名、学号、性别、年龄等信息，将其保存到文件中。

2. 修改学生信息：根据学生的学号或者姓名，找到对应的学生信息并修改。

3. 删除学生信息：根据学生的学号或者姓名，找到对应的学生信息并从文件中删除。

4. 查询学生信息：根据学生的学号或者姓名，找到对应的学生信息并打印出来。

5. 统计学生信息：统计总人数、男女人数、平均年龄等信息。

下面是一个简单的示例代码实现：

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

struct student {
    char name[20];
    int id;
    char gender[10];
    int age;
};

void add_student(struct student *stu, FILE *fp);
void modify_student(struct student *stu, FILE *fp);
void delete_student(struct student *stu, FILE *fp);
void query_student(struct student *stu, FILE *fp);
void statistic_student(struct student *stu, FILE *fp);

int main() {
    struct student stu;
    FILE *fp = fopen("student.txt", "a+"); // 打开文件
    int choice;
    do {
        printf("\n\n\t\t\t\tStudent Information Management System\n");
        printf("\t\t\t===============================================\n");
        printf("\t\t\t1. Add Student Information\n");
        printf("\t\t\t2. Modify Student Information\n");
        printf("\t\t\t3. Delete Student Information\n");
        printf("\t\t\t4. Query Student Information\n");
        printf("\t\t\t5. Statistic Student Information\n");
        printf("\t\t\t6. Exit\n");
        printf("\t\t\t===============================================\n");
        printf("\t\t\tEnter your choice: ");
        scanf("%d", &choice);
        switch (choice) {
            case 1:
                add_student(&stu, fp);
                break;
            case 2:
                modify_student(&stu, fp);
                break;
            case 3:
                delete_student(&stu, fp);
                break;
            case 4:
                query_student(&stu, fp);
                break;
            case 5:
                statistic_student(&stu, fp);
                break;
            case 6:
                printf("Exiting...\n");
                break;
            default:
                printf("Invalid choice. Please try again.\n");
                break;
        }
    } while (choice != 6);
    fclose(fp); // 关闭文件
    return 0;
}

void add_student(struct student *stu, FILE *fp) {
    printf("\nEnter Student Name: ");
    scanf("%s", stu->name);
    printf("Enter Student ID: ");
    scanf("%d", &stu->id);
    printf("Enter Student Gender: ");
    scanf("%s", stu->gender);
    printf("Enter Student Age: ");
    scanf("%d", &stu->age);
    fwrite(stu, sizeof(struct student), 1, fp); // 将学生信息写入文件
    printf("\nStudent Information Added Successfully!\n");
}

void modify_student(struct student *stu, FILE *fp) {
    int id;
    char name[20];
    printf("\nEnter Student ID or Name to Modify: ");
    scanf("%s", name);
    fseek(fp, 0, SEEK_SET); // 将文件指针移动到文件开头
    while (fread(stu, sizeof(struct student), 1, fp) == 1) {
        if (strcmp(stu->name, name) == 0 || stu->id == atoi(name)) { // 根据学号或姓名找到对应学生信息
            printf("Enter New Student Name: ");
            scanf("%s", stu->name);
            printf("Enter New Student ID: ");
            scanf("%d", &stu->id);
            printf("Enter New Student Gender: ");
            scanf("%s", stu->gender);
            printf("Enter New Student Age: ");
            scanf("%d", &stu->age);
            fseek(fp, -sizeof(struct student), SEEK_CUR); // 将文件指针移动到当前学生信息的位置
            fwrite(stu, sizeof(struct student), 1, fp); // 将修改后的学生信息写入文件
            printf("\nStudent Information Modified Successfully!\n");
            return;
        }
    }
    printf("\nStudent Information Not Found!\n");
}

void delete_student(struct student *stu, FILE *fp) {
    int id;
    char name[20];
    printf("\nEnter Student ID or Name to Delete: ");
    scanf("%s", name);
    FILE *temp = fopen("temp.txt", "w"); // 打开临时文件
    fseek(fp, 0, SEEK_SET); // 将文件指针移动到文件开头
    while (fread(stu, sizeof(struct student), 1, fp) == 1) {
        if (strcmp(stu->name, name) != 0 && stu->id != atoi(name)) { // 将不需要删除的学生信息写入临时文件
            fwrite(stu, sizeof(struct student), 1, temp);
        }
    }
    fclose(fp);
    fclose(temp);
    remove("student.txt"); // 删除原文件
    rename("temp.txt", "student.txt"); // 重命名临时文件
    fp = fopen("student.txt", "a+"); // 重新打开文件
    printf("\nStudent Information Deleted Successfully!\n");
}

void query_student(struct student *stu, FILE *fp) {
    int id;
    char name[20];
    printf("\nEnter Student ID or Name to Query: ");
    scanf("%s", name);
    fseek(fp, 0, SEEK_SET); // 将文件指针移动到文件开头
    while (fread(stu, sizeof(struct student), 1, fp) == 1) {
        if (strcmp(stu->name, name) == 0 || stu->id == atoi(name)) { // 根据学号或姓名找到对应学生信息并打印
            printf("\nStudent Name: %s\n", stu->name);
            printf("Student ID: %d\n", stu->id);
            printf("Student Gender: %s\n", stu->gender);
            printf("Student Age: %d\n", stu->age);
            return;
        }
    }
    printf("\nStudent Information Not Found!\n");
}

void statistic_student(struct student *stu, FILE *fp) {
    int total = 0, male = 0, female = 0, age_total = 0;
    float age_avg;
    fseek(fp, 0, SEEK_SET); // 将文件指针移动到文件开头
    while (fread(stu, sizeof(struct student), 1, fp) == 1) {
        total++; // 总人数加1
        if (strcmp(stu->gender, "male") == 0) {
            male++; // 男生人数加1
        } else if (strcmp(stu->gender, "female") == 0) {
            female++; // 女生人数加1
        }
        age_total += stu->age; // 年龄累加
    }
    age_avg = (float)age_total / total; // 平均年龄计算
    printf("\nTotal Number of Students: %d\n", total);
    printf("Number of Male Students: %d\n", male);
    printf("Number of Female Students: %d\n", female);
    printf("Average Age of Students: %.2f\n", age_avg);
}

注意，在上面的代码中，我们将学生信息保存在了一个文件中，每个学生信息占用一个固定大小的结构体。当需要修改或删除学生信息时，我们需要先找到对应的学生信息在文件中的位置，然后再进行操作。当需要查询或统计学生信息时，我们需要遍历整个文件并逐个处理每个学生信息。