题目：学生籍贯管理系统 内容：编制一个学生籍贯信息记录簿，每个学生信息包括：学号、姓名、籍贯、通信地址，以顺序存储结构设计程序实现以下功能。 1、输入学生信息并以磁盘文件保存； 2、读取磁盘文件并显示输出所有学生的籍贯信息； 3、按学号或姓名查询其籍贯； 4、按籍贯查询并输出该籍贯的所有学生； 5、能添加、删除（按学号）和修改（按学号）学生的籍贯信息； 6、显示输出上海籍和非上海籍学生的信息并可分别存盘； 7、浏览所有学生的籍贯信息； 8、按学号进行排序。

以下是一个基于C语言的学生籍贯管理系统的简单实现：

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

// 学生信息结构体
typedef struct {
    char id[10]; // 学号
    char name[20]; // 姓名
    char hometown[20]; // 籍贯
    char address[50]; // 通信地址
} Student;

// 存储所有学生信息的数组
Student students[100];

// 学生数量
int studentCount = 0;

// 从文件中读取学生信息
void readStudentsFromFile(char *fileName) {
    FILE *fp = fopen(fileName, "r");
    if (fp == NULL) {
        printf("File %s not found.\n", fileName);
        return;
    }
    // 逐行读取学生信息
    while (feof(fp) == 0) {
        Student student;
        fscanf(fp, "%s %s %s %s", student.id, student.name, student.hometown, student.address);
        students[studentCount] = student;
        studentCount++;
    }
    fclose(fp);
}

// 将所有学生信息保存到文件中
void saveStudentsToFile(char *fileName) {
    FILE *fp = fopen(fileName, "w");
    for (int i = 0; i < studentCount; i++) {
        fprintf(fp, "%s %s %s %s\n", students[i].id, students[i].name, students[i].hometown, students[i].address);
    }
    fclose(fp);
}

// 添加学生
void addStudent() {
    Student student;
    printf("Enter student's id: ");
    scanf("%s", student.id);
    printf("Enter student's name: ");
    scanf("%s", student.name);
    printf("Enter student's hometown: ");
    scanf("%s", student.hometown);
    printf("Enter student's address: ");
    scanf("%s", student.address);
    students[studentCount] = student;
    studentCount++;
}

// 删除学生
void deleteStudent() {
    char id[10];
    printf("Enter student's id to delete: ");
    scanf("%s", id);
    int index = -1;
    for (int i = 0; i < studentCount; i++) {
        if (strcmp(students[i].id, id) == 0) {
            index = i;
            break;
        }
    }
    if (index != -1) {
        for (int i = index; i < studentCount; i++) {
            students[i] = students[i + 1];
        }
        studentCount--;
        printf("Student with id %s deleted.\n", id);
    } else {
        printf("Student with id %s not found.\n", id);
    }
}

// 修改学生
void modifyStudent() {
    char id[10];
    printf("Enter student's id to modify: ");
    scanf("%s", id);
    int index = -1;
    for (int i = 0; i < studentCount; i++) {
        if (strcmp(students[i].id, id) == 0) {
            index = i;
            break;
        }
    }
    if (index != -1) {
        printf("Enter new hometown for student with id %s: ", id);
        scanf("%s", students[index].hometown);
        printf("Enter new address for student with id %s: ", id);
        scanf("%s", students[index].address);
        printf("Student with id %s modified.\n", id);
    } else {
        printf("Student with id %s not found.\n", id);
    }
}

// 按学号或姓名查询学生
void searchStudent() {
    int option;
    printf("Search by (1) id or (2) name? ");
    scanf("%d", &option);
    char keyword[20];
    printf("Enter keyword: ");
    scanf("%s", keyword);
    for (int i = 0; i < studentCount; i++) {
        if (option == 1 && strcmp(students[i].id, keyword) == 0) {
            printf("%s %s %s %s\n", students[i].id, students[i].name, students[i].hometown, students[i].address);
        } else if (option == 2 && strcmp(students[i].name, keyword) == 0) {
            printf("%s %s %s %s\n", students[i].id, students[i].name, students[i].hometown, students[i].address);
        }
    }
}

// 按籍贯查询学生
void searchByHometown() {
    char hometown[20];
    printf("Enter hometown: ");
    scanf("%s", hometown);
    for (int i = 0; i < studentCount; i++) {
        if (strcmp(students[i].hometown, hometown) == 0) {
            printf("%s %s %s %s\n", students[i].id, students[i].name, students[i].hometown, students[i].address);
        }
    }
}

// 显示所有学生信息
void displayAllStudents() {
    for (int i = 0; i < studentCount; i++) {
        printf("%s %s %s %s\n", students[i].id, students[i].name, students[i].hometown, students[i].address);
    }
}

// 显示上海籍和非上海籍学生信息
void displayShanghaiStudents() {
    FILE *shanghaiFile = fopen("shanghai.txt", "w");
    FILE *nonShanghaiFile = fopen("non_shanghai.txt", "w");
    for (int i = 0; i < studentCount; i++) {
        if (strcmp(students[i].hometown, "Shanghai") == 0) {
            fprintf(shanghaiFile, "%s %s %s %s\n", students[i].id, students[i].name, students[i].hometown, students[i].address);
        } else {
            fprintf(nonShanghaiFile, "%s %s %s %s\n", students[i].id, students[i].name, students[i].hometown, students[i].address);
        }
    }
    fclose(shanghaiFile);
    fclose(nonShanghaiFile);
}

// 按学号排序
void sortStudentsById() {
    for (int i = 0; i < studentCount - 1; i++) {
        for (int j = 0; j < studentCount - i - 1; j++) {
            if (strcmp(students[j].id, students[j + 1].id) > 0) {
                Student temp = students[j];
                students[j] = students[j + 1];
                students[j + 1] = temp;
            }
        }
    }
}

int main() {
    char fileName[50] = "students.txt";
    int option = 0;
    // 读取学生信息文件
    readStudentsFromFile(fileName);
    while (option != 9) {
        printf("\nPlease choose an option:\n");
        printf("1. Add student\n");
        printf("2. Delete student\n");
        printf("3. Modify student\n");
        printf("4. Search student\n");
        printf("5. Search by hometown\n");
        printf("6. Display all students\n");
        printf("7. Display Shanghai and non-Shanghai students\n");
        printf("8. Sort students by id\n");
        printf("9. Exit\n");
        scanf("%d", &option);
        switch (option) {
            case 1:
                addStudent();
                break;
            case 2:
                deleteStudent();
                break;
            case 3:
                modifyStudent();
                break;
            case 4:
                searchStudent();
                break;
            case 5:
                searchByHometown();
                break;
            case 6:
                displayAllStudents();
                break;
            case 7:
                displayShanghaiStudents();
                break;
            case 8:
                sortStudentsById();
                printf("Students sorted by id.\n");
                break;
            case 9:
                printf("Saving students to file %s...\n", fileName);
                saveStudentsToFile(fileName);
                printf("Students saved to file.\n");
                break;
            default:
                printf("Invalid option.\n");
                break;
        }
    }
    return 0;
}

该程序使用了一个结构体来存储学生信息，并通过一个数组来存储所有学生信息。程序实现了输入学生信息、读取磁盘文件、查询学生籍贯、添加、删除和修改学生信息、分别显示上海籍和非上海籍学生信息、浏览所有学生信息、按学号排序等功能。