2020-07-07日报博客

2020-07-07日报博客

1.今天完成的事情：

• 学习Java，听黑马系列的视频教程前30集。

• 完成面向对象程序设计小学期第八个练习：学生成绩管理程序（链表）

• 代码如下：

  #include<iostream>
  #include<fstream>
  #include<iomanip>
  using namespace std;
  
  const int M = 1024;
  
  struct StudentInfo
  {
  public:
  	long studentId;
  	string name;
  	float math;
  	float Chinese;
  	float English;
  
  	StudentInfo* next = NULL;
  };
  class StudentManage {
  public:
  	StudentInfo* head = new StudentInfo;
  	string createFile();
  	string importFile();
  	void show();
  	void inputInfo();
  	void deleteInfo();
  	void changeInfo();
  	void findInfo();
  	void summary(float sum[], float average[]);
  	void sort(float sum[]);
  	void exportFile();
  	void insert();
  };
  
  string StudentManage::createFile()
  {
  	string fileName;
  	cout << "请输入文件名：";
  	cin >> fileName;
  	ofstream outfile(fileName, ios::out);
  	if (!outfile)
  	{
  		cerr << "创建失败！" << endl;
  	}
  	outfile.close();
  	return fileName;
  }
  string StudentManage::importFile() {
  	string fileName;
  	cout << "请输入文件名: ";
  	cin >> fileName;
  	ifstream infile(fileName, ios::in || ios::_Noreplace);
  	if (!infile)
  	{
  		cerr << "打开失败！" << endl;
  	}
  
  	head->next = NULL;
  	StudentInfo* pre = this->head;
  	while (!infile.eof()) {
  		StudentInfo* p = new StudentInfo;
  		infile >> p->studentId >> p->name >> p->math >> p->Chinese >> p->English;
  		if (infile.eof()) {
  			p->next = NULL;
  			break;
  		}
  		pre->next = p;
  		pre = p;
  		p->next = NULL;
  	}
  
  	this->show();
  	infile.close();
  	return fileName;
  }
  void StudentManage::show() {
  	cout << setw(10) << setiosflags(ios::left) << "学号  |" << setw(10) << setiosflags(ios::left) << "姓名  |" << setw(10) << setiosflags(ios::left) << "数学  |" << setw(10) << setiosflags(ios::left) << "语文  |" << setw(10) << setiosflags(ios::left) << "英语" << endl;
  	StudentInfo* p = this->head->next;
  	while (true) {
  		if (p == NULL || p->math < 0 || p->math > 100)
  			break;
  		cout << setw(10) << setiosflags(ios::left) << p->studentId << setw(10) << setiosflags(ios::left) << p->name << setw(10) << setiosflags(ios::left) << p->math << setw(10) << setiosflags(ios::left) << p->Chinese << setw(10) << setiosflags(ios::left) << p->English << endl;
  		if (p->next == NULL)
  			break;
  		p = p->next;
  	}
  }
  void StudentManage::inputInfo() {
  	int n;
  	cout << "请输入需要输入的人数：";
  	cin >> n;
  	cout << "开始输入学生信息：" << endl;
  	StudentInfo* pEnd = this->head;
  	while (true) {
  		pEnd = pEnd->next;
  		if (pEnd->next == NULL || pEnd->next->math < 0 || pEnd->next->math> 100)
  			break;
  	}
  	StudentInfo* pre = pEnd;
  	for (int i = 0; i < n; i++)
  	{
  		StudentInfo* p = new StudentInfo;
  		cin >> p->studentId >> p->name >> p->math >> p->Chinese >> p->English;
  		pre->next = p;
  		pre = p;
  		p->next = NULL;
  	}
  }
  void StudentManage::deleteInfo() {
  	if (head->next == NULL) {
  		cout << "数据未录入！" << endl;
  		return;
  	}
  	long id;
  	cout << "请输入学生学号: " << endl;
  	cin >> id;
  	StudentInfo* p = this->head->next;
  	while (true) {
  		if (p == NULL || p->math < 0 || p->math > 100)
  			break;
  		if (p->next->studentId == id) {
  			p->next = p->next->next;
  		}
  		p = p->next;
  	}
  }
  void StudentManage::changeInfo() {
  	if (head->next == NULL) {
  		cout << "数据未录入！" << endl;
  		return;
  	}
  	long id;
  	cout << "请输入学生学号: " << endl;
  	cin >> id;
  	StudentInfo* p = this->head->next;
  	while (true) {
  		if (p == NULL || p->math < 0 || p->math > 100)
  			break;
  		if (p->studentId == id) {
  			cout << "请重新输入该学生信息：" << endl;
  			cout << setw(10) << setiosflags(ios::left) << "学号  |" << setw(10) << setiosflags(ios::left) << "姓名  |" << setw(10) << setiosflags(ios::left) << "数学  |" << setw(10) << setiosflags(ios::left) << "语文  |" << setw(10) << setiosflags(ios::left) << "英语" << endl;
  			cin >> p->studentId >> p->name >> p->math >> p->Chinese >> p->English;
  		}
  		p = p->next;
  	}
  }
  void StudentManage::findInfo() {
  	if (head->next == NULL) {
  		cout << "数据未录入！" << endl;
  		return;
  	}
  	long id;
  	cout << "请输入学生学号: " << endl;
  	cin >> id;
  	StudentInfo* p = this->head->next;
  	while (true) {
  		if (p == NULL || p->math < 0 || p->math > 100)
  			break;
  		if (p->studentId == id) {
  			cout << "该生信息为：" << endl;
  			cout << setw(10) << setiosflags(ios::left) << "学号  |" << setw(10) << setiosflags(ios::left) << "姓名  |" << setw(10) << setiosflags(ios::left) << "数学  |" << setw(10) << setiosflags(ios::left) << "语文  |" << setw(10) << setiosflags(ios::left) << "英语" << endl;
  			cout << setw(10) << setiosflags(ios::left) << p->studentId << setw(10) << setiosflags(ios::left) << p->name << setw(10) << setiosflags(ios::left) << p->math << setw(10) << setiosflags(ios::left) << p->Chinese << setw(10) << setiosflags(ios::left) << p->English << endl;
  		}
  		p = p->next;
  	}
  }
  void StudentManage::summary(float sum[M], float average[M]) {
  	if (head->next == NULL) {
  		cout << "数据未录入！" << endl;
  		return;
  	}
  	StudentInfo* p = this->head->next;
  	int i = 0;
  	cout << setw(10) << setiosflags(ios::left) << "学号  |" << setw(10) << setiosflags(ios::left) << "姓名  |" << setw(10) << setiosflags(ios::left) << "数学  |" << setw(10) << setiosflags(ios::left) << "语文  |" << setw(10) << setiosflags(ios::left) << "英语  |" << "总分  |" << "平均分" << endl;
  	while (true) {
  		if (p == NULL || p->math < 0 || p->math > 100)
  			break;
  
  		sum[i] = p->math + p->Chinese + p->English;
  		average[i] = sum[i] / 3.0;
  
  		cout << setw(10) << setiosflags(ios::left) << p->studentId << setw(10) << setiosflags(ios::left) << p->name << setw(10) << setiosflags(ios::left) << p->math << setw(10) << setiosflags(ios::left) << p->Chinese << setw(10) << setiosflags(ios::left) << p->English << setw(10) << setiosflags(ios::left) << sum[i] << average[i] << endl;
  
  		p = p->next;
  	}
  }
  void Swap(StudentInfo& a, StudentInfo& b) {
  	StudentInfo t;
  	t.studentId = a.studentId;
  	t.name = a.name;
  	t.math = a.math;
  	t.Chinese = a.Chinese;
  	t.English = a.English;
  
  	a.studentId = b.studentId;
  	a.name = b.name;
  	a.math = b.math;
  	a.Chinese = b.Chinese;
  	a.English = b.English;
  
  	b.studentId = t.studentId;
  	b.name = t.name;
  	b.math = t.math;
  	b.Chinese = t.Chinese;
  	b.English = t.English;
  }
  void StudentManage::sort(float sum[]) {
  	if (head->next == NULL) {
  		cout << "数据未录入！" << endl;
  		return;
  	}
  	int a, N = 0;
  	StudentInfo* p = this->head->next;
  	while (true) {
  		if (p == NULL || p->math < 0 || p->math > 100)
  			break;
  		N++;
  		p = p->next;
  	}
  	cout << N << endl;
  	cout << "请选择按学号还是按总分排序（1.学号 2.总分）：";
  	cin >> a;
  	if (a == 1) {
  		for (int i = 1; i < N - 1; i++)
  		{
  			StudentInfo* p = NULL;
  			StudentInfo* q = NULL;
  			StudentInfo* t = NULL;
  
  			if (this->head == NULL || (this->head)->next == NULL)
  			{
  				return;
  			}
  
  			for (p = this->head; p != NULL; p = p->next)
  			{
  				t = p;
  
  				for (q = p->next; q != NULL; q = q->next)
  				{
  					if (q->studentId < t->studentId)
  					{
  						t = q;
  					}
  				}
  
  				if (t != p)
  				{
  					Swap(*t, *p);
  				}
  			}
  		}
  		this->show();
  	}
  	if (a == 2) {
  		StudentInfo* p1 = NULL;
  		StudentInfo* q = NULL;
  		StudentInfo* t = NULL;
  
  		if (this->head == NULL || (this->head)->next == NULL)
  		{
  			return;
  		}
  
  		for (p1 = this->head->next; p1 != NULL; p1 = p1->next)
  		{
  			for (q = this->head->next; q->next != NULL; q = q->next)
  			{
  				if ((q->math + q->Chinese + q->English) < (q->next->math + q->next->Chinese + q->next->English))
  				{
  					Swap(*q, *q->next);
  				}
  			}
  		}
  
  		StudentInfo* p = this->head->next;
  		cout << setw(10) << setiosflags(ios::left) << "学号  |" << setw(10) << setiosflags(ios::left) << "姓名  |" << setw(10) << setiosflags(ios::left) << "数学  |" << setw(10) << setiosflags(ios::left) << "语文  |" << setw(10) << setiosflags(ios::left) << "英语  |" << "总分" << endl;
  		while (true) {
  			if (p == NULL || p->math < 0 || p->math > 100)
  				break;
  
  			double sum = p->math + p->Chinese + p->English;
  
  			cout << setw(10) << setiosflags(ios::left) << p->studentId << setw(10) << setiosflags(ios::left) << p->name << setw(10) << setiosflags(ios::left) << p->math << setw(10) << setiosflags(ios::left) << p->Chinese << setw(10) << setiosflags(ios::left) << p->English << setw(10) << setiosflags(ios::left) << sum << endl;
  
  			p = p->next;
  		}
  	}
  	if (a != 1 && a != 2) {
  		cout << "不存在该选项！" << endl;
  	}
  }
  void StudentManage::exportFile() {
  	string fileName;
  	cout << "请输入文件名：";
  	cin >> fileName;
  	ofstream outfile(fileName, ios::out);
  	if (!outfile)
  	{
  		cerr << "Open error!" << endl;
  		exit(1);
  	}
  
  	StudentInfo* p = this->head->next;
  	while (true) {
  		if (p == NULL || p->math < 0 || p->math > 100)
  			break;
  		outfile << setw(10) << setiosflags(ios::left) << p->studentId << setw(10) << setiosflags(ios::left) << p->name << setw(10) << setiosflags(ios::left) << p->math << setw(10) << setiosflags(ios::left) << p->Chinese << setw(10) << setiosflags(ios::left) << p->English << endl;
  		if (p->next == NULL)
  			break;
  		p = p->next;
  	}
  
  	outfile.close();
  	cout << "写入完成！" << endl;
  }
  void StudentManage::insert() {
  	int n, t, N;
  	cout << "请输入要插入的学生数n：";
  	cin >> n;
  	cout << "请输入位置：";
  	cin >> t;
  
  	StudentInfo* p = this->head->next;
  	for (int i = 0; i < t - 3; i++) {
  		if (p == NULL || p->next == NULL || p->math < 0 || p->math > 100)
  			break;
  		p = p->next;
  	}
  	for (int i = 0; i < n; i++) {
  		StudentInfo* t = p->next;
  		p->next = new StudentInfo;
  		cout << "请输入要插入学生的信息：" << endl;
  		cin >> p->next->studentId >> p->next->name >> p->next->math >> p->next->Chinese >> p->next->English;
  		p->next->next = t;
  
  		p = p->next;
  	}
  }
  
  int main() {
  	StudentManage classA;
  	string filename;
  	float sum[M], average[M];
  	int a;
  	cout << "学生成绩管理系统：
  1 创建
  2 导入
  3 显示
  4 输入
  5 删除
  6 修改
  7 查询
  8 汇总
  9 排序
  10 导出
  11 插入
  12 退出
  ";
  	while (true) {
  		cout << "请选择：";
  		cin >> a;
  		switch (a) {
  		case 1:filename = classA.createFile(); continue;
  		case 2:filename = classA.importFile(); continue;
  		case 3:classA.show(); continue;
  		case 4:classA.inputInfo(); continue;
  		case 5:classA.deleteInfo(); continue;
  		case 6:classA.changeInfo(); continue;
  		case 7:classA.findInfo(); continue;
  		case 8:classA.summary(sum, average); continue;
  		case 9:classA.sort(sum); continue;
  		case 10:classA.exportFile(); continue;
  		case 11:classA.insert(); continue;
  		case 12: {
  			exit(0);
  		}
  		default:cout << "不存在该选项！" << endl; continue;
  		}
  	}
  	return 0;
  }
  

2.遇到的问题：

• 链表的一些操作，如排序，已通过搜索引擎解决。

3.明天的计划：

• 继续完成小学期任务，继续学习Java。