学生成绩管理系统（C++实现）
学生成绩表信息包括学号、姓名、各科课程成绩（语文、数学、英语、政治）和总分。用带头结点的单链表管理学生成绩表，每个学生的信息依次从键盘输入，并根据需要进行插入、删除、排序、输出等操作。
#include
#include
#include
#include
const int MAX_STUDENTS = 100;
struct Student {
char ID[20];
char Name[10];
float Math;
float English;
float Chinese;
float Total;
float Average;
};
int num = 0;
Student students[MAX_STUDENTS];
void saveToFile() {
std::ofstream file("C:/Users/Lenovo/Desktop/111.txt");
if (!file.is_open()) {
std::cout << "无法打开文件。" << std::endl;
return;
}
file << num << std::endl;
for (int i = 0; i < num; ++i) {
file << students[i].ID << " " << students[i].Name << " " << students[i].Math << " "
<< students[i].English << " " << students[i].Chinese << " " << students[i].Total << " "
<< students[i].Average << std::endl;
}
file.close();
}
void loadFromFile() {
std::ifstream file("C:/Users/Lenovo/Desktop/111.txt");
if (!file.is_open()) {
std::cout << "无法打开文件。" << std::endl;
return;
}
file >> num;
for (int i = 0; i < num; ++i) {
file >> students[i].ID >> students[i].Name >> students[i].Math
>> students[i].English >> students[i].Chinese >> students[i].Total >> students[i].Average;
}
file.close();
}
void input() {
if (num >= MAX_STUDENTS) {
std::cout << "学生人数已达到上限，无法继续添加。" << std::endl;
return;
}
std::cout << "请输入学号：";
std::cin >> students[num].ID;
std::cout << "请输入姓名：";
std::cin >> students[num].Name;
std::cout << "请输入数学成绩：";
std::cin >> students[num].Math;
std::cout << "请输入英语成绩：";
std::cin >> students[num].English;
std::cout << "请输入语文成绩：";
std::cin >> students[num].Chinese;
students[num].Total = students[num].Math + students[num].English + students[num].Chinese;
students[num].Average = students[num].Total / 3;
num++;
std::cout << "录入成功。" << std::endl;
saveToFile();
}
void deleteStudent() {
char deleteID[20];
std::cout << "请输入要删除的学生学号：";
std::cin >> deleteID;
for (int i = 0; i < num; ++i) {
if (strcmp(students[i].ID, deleteID) == 0) {
for (int j = i; j < num - 1; ++j) {
students[j] = students[j + 1];
}
num--;
std::cout << "删除成功。" << std::endl;
saveToFile();
return;
}
}
std::cout << "未找到学号为" << deleteID << "的学生。" << std::endl;
}
void modify() {
char modifyID[20];
std::cout << "请输入要修改的学生学号：";
std::cin >> modifyID;
for (int i = 0; i < num; ++i) {
if (strcmp(students[i].ID, modifyID) == 0) {
std::cout << "请输入新的数学成绩：";
std::cin >> students[i].Math;
std::cout << "请输入新的英语成绩：";
std::cin >> students[i].English;
std::cout << "请输入新的语文成绩：";
std::cin >> students[i].Chinese;
students[i].Total = students[i].Math + students[i].English + students[i].Chinese;
students[i].Average = students[i].Total / 3;
std::cout << "修改成功。" << std::endl;
saveToFile();
return;
}
}
std::cout << "未找到学号为" << modifyID << "的学生。" << std::endl;
}
void insert() {
if (num >= MAX_STUDENTS) {
std::cout << "学生人数已达到上限，无法插入。" << std::endl;
return;
}
int position;
std::cout << "请输入要插入的位置（1-" << num + 1 << "）：";
std::cin >> position;
if (position < 1 || position > num + 1) {
std::cout << "位置无效，请重新输入。" << std::endl;
return;
}
for (int i = num; i >= position
; --i) {
students[i] = students[i - 1];
}
std::cout << "请输入学号：";
std::cin >> students[position - 1].ID;
std::cout << "请输入姓名：";
std::cin >> students[position - 1].Name;
std::cout << "请输入数学成绩：";
std::cin >> students[position - 1].Math;
std::cout << "请输入英语成绩：";
std::cin >> students[position - 1].English;
std::cout << "请输入语文成绩：";
std::cin >> students[position - 1].Chinese;
students[position - 1].Total = students[position - 1].Math + students[position - 1].English + students[position - 1].Chinese;
students[position - 1].Average = students[position - 1].Total / 3;
num++;
std::cout << "插入成功。" << std::endl;
saveToFile();
}
void sort() {
for (int i = 0; i < num - 1; ++i) {
for (int j = 0; j < num - i - 1; ++j) {
if (students[j].Average < students[j + 1].Average) {
std::swap(students[j], students[j + 1]);
}
}
}
std::cout << "排序完成。" << std::endl;
saveToFile();
}
void display() {
if (num == 0) {
std::cout << "暂无学生信息。" << std::endl;
return;
}
std::cout << "学号\t姓名\t数学\t英语\t语文\t总分\t平均分" << std::endl;
for (int i = 0; i < num; ++i) {
std::cout << students[i].ID << '\t' << students[i].Name << '\t' << students[i].Math << '\t'
<< students[i].English << '\t' << students[i].Chinese << '\t' << students[i].Total
<< '\t' << students[i].Average << std::endl;
}
}
void searchByIndex() {
char searchID[20];
std::cout << "请输入要查询的学生学号：";
std::cin >> searchID;
for (int i = 0; i < num; ++i) {
if (strcmp(students[i].ID, searchID) == 0) {
std::cout << "学号：" << students[i].ID << "，姓名：" << students[i].Name << "，数学：" << students[i].Math << "，英语：" << students[i].English << "，语文：" << students[i].Chinese << "，总分：" << students[i].Total << "，平均分：" << students[i].Average << std::endl;
return;
}
}
std::cout << "未找到学号为" << searchID << "的学生。" << std::endl;
}
int main() {
loadFromFile(); // 在程序开始时加载学生数据
int choice;
while (true) {
std::cout << "=========学生成绩管理系统=========" << std::endl;
std::cout << "1. 录入学生成绩" << std::endl;
std::cout << "2. 删除学生成绩" << std::endl;
std::cout << "3. 修改学生成绩" << std::endl;
std::cout << "4. 插入学生成绩" << std::endl;
std::cout << "5. 排序学生成绩" << std::endl;
std::cout << "6. 显示学生成绩" << std::endl;
std::cout << "7. 查询学生成绩" << std::endl;
std::cout << "0. 退出" << std::endl;
std::cout << "=================================" << std::endl;
std::cout << "请选择操作：";
std::cin >> choice;
switch (choice) {
case 1:
input();
break;
case 2:
deleteStudent();
break;
case 3:
modify();
break;
case 4:
insert();
break;
case 5:
sort();
break;
case 6:
display();
break;
case 7:
searchByIndex();
break;
case 0:
std::cout << "感谢使用学生成绩管理系统，再见！" << std::endl;
saveToFile(); // 在程序结束时保存学生数据
return 0;
default:
std::cout << "输入无效，请重新输入。" << std::endl;
}
}
return 0;
}