如何通过键盘或乐谱文件输入乐谱
How to enter the scores via the keyboard or from a scores file
#include <iostream>
#include <string>
#include <fstream>
using namespace std;
void getInformationKeyBoard(int size, string Names[], int socres[]);
void getInformationFile(fstream& FileName, int size, string Names[], int scores[]);
void OpenTheFile(ifstream& FileName);
int main()
{
const int size = 1024;
string Name[size];
int score[size];
int NumberOfStudent;
char choice;
cout << "You want to enter your scores by your keyboard (A) or from your input (B): ";
cin >> choice;
if (choice == 'a' || choice == 'A') // It will take information from keyboard
{
cout << "How many students do you want to enter: ";
cin >> NumberOfStudent;
getInformationKeyBoard(NumberOfStudent, Name, score);
}
else if (choice == 'b' || choice == 'B') // It will take information from file
{
ifstream FileName;
OpenTheFile(FileName);
FileName >> NumberOfStudent;
getInformationFile(FileName, NumberOfStudent, Name, score);
FileName.close;
}
else // If you choice is not A,a or B,b
cout << "Your did not follow the right instruction.";
}
void getInformationKeyBoard(int size, string Names[], int scores[]) // Information from keyboard
{
for (int i = 0; i < size; i++)
{
cout << i + 1 << ". Student First Name and Last Name: ";
cin.ignore();
getline(cin, Names[1]);
do
{
cout << i + 1 << ". Enter the score between 1 and 100: ";
cin >> scores[i];
} while (scores[i] > 100 || scores[i] < 0 );
}
}
void OpenTheFile(ifstream& FileName) // Open the File
{
char again;
string InputFile;
bool close = false;
while (close == false)
{
cout << "Open the file: ";
cin >> InputFile;
ifstream ReadFromFile(InputFile);
if (ReadFromFile.is_open())
{
cout << "Succeed to open the file!\n";
close = true;
}
else
{
cout << "Failed to open the file!\n";
do {
cout << "Do you want to do it again(Y) or Close (N)? ";
cin >> again;
} while (again != 'y' && again != 'Y' && again != 'n' && again != 'N');
if (again == 'y' || again == 'Y')
close = false;
else
close = true;
}
}
}
void getInformationFile(ifstream& FileName, int size, string Names[], int scores[]) // Get information from the File
{
string FName, LName;
for (int i = 0; i < size; i++)
{
FileName >> FName >> LName;
Names[i] = FName + " " + LName;
FileName >> scores[i];
}
}
当用户输入 B 打开乐谱文件时，我的程序没有继续。谁能帮我解决这个问题。
- 如果用户选择键盘，那么应该首先询问用户他们想要输入的分数总数，然后询问用户每个学生的姓名和考试分数。
如果用户选择文件，则询问用户文件名和位置。文件中的第一行应该是分数总数，后面是一个学生姓名和每行他们的测试分数。
例如：
3
F1 L1
82
F2 L2
87
F3 L3
92
而且我想知道如何为
提供更多功能
- 确定最低分
- 确定最高分
- 计算mean/average分
我只是一个C++的初学者，请简单点，这样我才能更好地理解程序
这些分配的更好方法是使用一个记录容器，而不是多个容器，每个容器包含一个元素。
让我们定义一条记录：
struct Score_Record
{
std::string first_name;
std::string last_name;
int score;
};
为简单起见，让我们选择一个向量作为我们的容器。为了节省击键次数，我们将使用 typedef:
typedef std::vector<Score_Record> Container_Type;
如果我们希望能够从文件或键盘加载记录，我们将使用通用流的概念：
void Input_Score(std::istream& input, Score_Record& sr)
{
input >> sr.first_name;
input >> sr.last_name;
input >> sr.score;
input.ignore(100000, '\n'); // Synchronize to next input line.
}
所以，要从键盘输入：
Score_Record sr;
Input_Record(cin, sr);
从文件输入：
ifstream data_file("my_data.txt");
Input_Record(data_file);
下面是一些查找最高分的代码：
Container_Type database;
// read into database
const size_t quantity = database.size();
int maximum_score = -1;
for (unsigned int i = 0; i < quantity; ++i)
{
if (database[i].score > maximum_score)
{
maximum_score = database[i].score;
}
}
最低点、平均值和均值可以类似于上面的循环计算。
编辑 1：更简单的解决方案
如果我们保留与 class 相关的所有事物分数的责任，我们可以让 class 从输入流中读取它的值：
class Score_Record
{
public:
Score_Record()
{ ; }
virtual ~Score_Record();
friend std::istream& operator>>(std::istream& input, Score_Record& sr);
private:
std::string first_name;
std::string last_name;
int score;
};
std::istream& operator>>(std::istream& input, Score_Record& sr)
{
input >> sr.first_name;
input >> sr.last_name;
input >> sr.score;
input.ignore(100000, '\n'); // synchronize to next text line.
return input;
}
要从文件中读取单个 Score_Record：
Score_Record sr;
data_file >> sr;
将整个文件读入数据库：
Container_Type database;
while (database >> sr)
{
database.push_back(sr);
}
#include <iostream>
#include <string>
#include <fstream>
using namespace std;
void getInformationKeyBoard(int size, string Names[], int socres[]);
void getName(string & name);
int main()
{
const int size = 1024;
string Name[size];
int score[size];
int NumberOfStudent;
char choice;
cout << "You want to enter your scores by your keyboard (A) or from your input (B): ";
cin >> choice;
if (choice == 'a' || choice == 'A') // It will take information from keyboard
{
cout << "How many students do you want to enter: ";
cin >> NumberOfStudent;
getInformationKeyBoard(NumberOfStudent, Name, score);
}
else if (choice == 'b' || choice == 'B') // It will take information from file
{
string NameA;
getName(NameA);
GetInformationFile(nameA, NumberOfStudent, Name, score); // This is where my program get an error
}
else // If you choice is not A,a or B,b
cout << "Your did not follow the right instruction.";
cout << endl << endl;
system("pause");
return 0;
}
void getInformationKeyBoard(int size, string Names[], int scores[]) // Information from keyboard
{
for (int i = 0; i < size; i++)
{
cout << i + 1 << ". Student First Name and Last Name: ";
cin.ignore();
getline(cin, Names[1]);
do
{
cout << i + 1 << ". Enter the score between 1 and 100: ";
cin >> scores[i];
} while (scores[i] > 100 || scores[i] < 0 );
}
}
void GetInformationFile(fstream name, int size, string Names[], int scores[])
{
for (int i = 0; i < size; i++)
{
string line;
getline(name, line);
Names[i];
scores[i];
}
}
void getName(string & name)
{
char again = 'Y';
bool close = false;
while (close == false)
{
cout << "Enter name of file: ";
cin >> name;
ifstream inFile;
inFile.open(name.c_str());
close = true;
if (!inFile)
{
cout << "File did not open correctly" << endl;
do
{
cout << "Do you want to do it again(Y) or Close (N): ";
cin >> again;
}
while (again != 'y' && again != 'Y' && again != 'n' && again != 'N');
if (again == 'y' || again == 'Y')
close = false;
else
close = true;
}
}
}
#include <iostream>
#include <string>
#include <fstream>
using namespace std;
void getInformationKeyBoard(int size, string Names[], int socres[]);
void getInformationFile(fstream& FileName, int size, string Names[], int scores[]);
void OpenTheFile(ifstream& FileName);
int main()
{
const int size = 1024;
string Name[size];
int score[size];
int NumberOfStudent;
char choice;
cout << "You want to enter your scores by your keyboard (A) or from your input (B): ";
cin >> choice;
if (choice == 'a' || choice == 'A') // It will take information from keyboard
{
cout << "How many students do you want to enter: ";
cin >> NumberOfStudent;
getInformationKeyBoard(NumberOfStudent, Name, score);
}
else if (choice == 'b' || choice == 'B') // It will take information from file
{
ifstream FileName;
OpenTheFile(FileName);
FileName >> NumberOfStudent;
getInformationFile(FileName, NumberOfStudent, Name, score);
FileName.close;
}
else // If you choice is not A,a or B,b
cout << "Your did not follow the right instruction.";
}
void getInformationKeyBoard(int size, string Names[], int scores[]) // Information from keyboard
{
for (int i = 0; i < size; i++)
{
cout << i + 1 << ". Student First Name and Last Name: ";
cin.ignore();
getline(cin, Names[1]);
do
{
cout << i + 1 << ". Enter the score between 1 and 100: ";
cin >> scores[i];
} while (scores[i] > 100 || scores[i] < 0 );
}
}
void OpenTheFile(ifstream& FileName) // Open the File
{
char again;
string InputFile;
bool close = false;
while (close == false)
{
cout << "Open the file: ";
cin >> InputFile;
ifstream ReadFromFile(InputFile);
if (ReadFromFile.is_open())
{
cout << "Succeed to open the file!\n";
close = true;
}
else
{
cout << "Failed to open the file!\n";
do {
cout << "Do you want to do it again(Y) or Close (N)? ";
cin >> again;
} while (again != 'y' && again != 'Y' && again != 'n' && again != 'N');
if (again == 'y' || again == 'Y')
close = false;
else
close = true;
}
}
}
void getInformationFile(ifstream& FileName, int size, string Names[], int scores[]) // Get information from the File
{
string FName, LName;
for (int i = 0; i < size; i++)
{
FileName >> FName >> LName;
Names[i] = FName + " " + LName;
FileName >> scores[i];
}
}
当用户输入 B 打开乐谱文件时，我的程序没有继续。谁能帮我解决这个问题。
- 如果用户选择键盘，那么应该首先询问用户他们想要输入的分数总数，然后询问用户每个学生的姓名和考试分数。
如果用户选择文件，则询问用户文件名和位置。文件中的第一行应该是分数总数，后面是一个学生姓名和每行他们的测试分数。 例如：
3 F1 L1 82 F2 L2 87 F3 L3 92
而且我想知道如何为
提供更多功能- 确定最低分
- 确定最高分
- 计算mean/average分
我只是一个C++的初学者，请简单点，这样我才能更好地理解程序
这些分配的更好方法是使用一个记录容器，而不是多个容器，每个容器包含一个元素。
让我们定义一条记录：
struct Score_Record
{
std::string first_name;
std::string last_name;
int score;
};
为简单起见，让我们选择一个向量作为我们的容器。为了节省击键次数，我们将使用 typedef:
typedef std::vector<Score_Record> Container_Type;
如果我们希望能够从文件或键盘加载记录，我们将使用通用流的概念：
void Input_Score(std::istream& input, Score_Record& sr)
{
input >> sr.first_name;
input >> sr.last_name;
input >> sr.score;
input.ignore(100000, '\n'); // Synchronize to next input line.
}
所以，要从键盘输入：
Score_Record sr;
Input_Record(cin, sr);
从文件输入：
ifstream data_file("my_data.txt");
Input_Record(data_file);
下面是一些查找最高分的代码：
Container_Type database;
// read into database
const size_t quantity = database.size();
int maximum_score = -1;
for (unsigned int i = 0; i < quantity; ++i)
{
if (database[i].score > maximum_score)
{
maximum_score = database[i].score;
}
}
最低点、平均值和均值可以类似于上面的循环计算。
编辑 1：更简单的解决方案
如果我们保留与 class 相关的所有事物分数的责任，我们可以让 class 从输入流中读取它的值：
class Score_Record
{
public:
Score_Record()
{ ; }
virtual ~Score_Record();
friend std::istream& operator>>(std::istream& input, Score_Record& sr);
private:
std::string first_name;
std::string last_name;
int score;
};
std::istream& operator>>(std::istream& input, Score_Record& sr)
{
input >> sr.first_name;
input >> sr.last_name;
input >> sr.score;
input.ignore(100000, '\n'); // synchronize to next text line.
return input;
}
要从文件中读取单个 Score_Record：
Score_Record sr;
data_file >> sr;
将整个文件读入数据库：
Container_Type database;
while (database >> sr)
{
database.push_back(sr);
}
#include <iostream>
#include <string>
#include <fstream>
using namespace std;
void getInformationKeyBoard(int size, string Names[], int socres[]);
void getName(string & name);
int main()
{
const int size = 1024;
string Name[size];
int score[size];
int NumberOfStudent;
char choice;
cout << "You want to enter your scores by your keyboard (A) or from your input (B): ";
cin >> choice;
if (choice == 'a' || choice == 'A') // It will take information from keyboard
{
cout << "How many students do you want to enter: ";
cin >> NumberOfStudent;
getInformationKeyBoard(NumberOfStudent, Name, score);
}
else if (choice == 'b' || choice == 'B') // It will take information from file
{
string NameA;
getName(NameA);
GetInformationFile(nameA, NumberOfStudent, Name, score); // This is where my program get an error
}
else // If you choice is not A,a or B,b
cout << "Your did not follow the right instruction.";
cout << endl << endl;
system("pause");
return 0;
}
void getInformationKeyBoard(int size, string Names[], int scores[]) // Information from keyboard
{
for (int i = 0; i < size; i++)
{
cout << i + 1 << ". Student First Name and Last Name: ";
cin.ignore();
getline(cin, Names[1]);
do
{
cout << i + 1 << ". Enter the score between 1 and 100: ";
cin >> scores[i];
} while (scores[i] > 100 || scores[i] < 0 );
}
}
void GetInformationFile(fstream name, int size, string Names[], int scores[])
{
for (int i = 0; i < size; i++)
{
string line;
getline(name, line);
Names[i];
scores[i];
}
}
void getName(string & name)
{
char again = 'Y';
bool close = false;
while (close == false)
{
cout << "Enter name of file: ";
cin >> name;
ifstream inFile;
inFile.open(name.c_str());
close = true;
if (!inFile)
{
cout << "File did not open correctly" << endl;
do
{
cout << "Do you want to do it again(Y) or Close (N): ";
cin >> again;
}
while (again != 'y' && again != 'Y' && again != 'n' && again != 'N');
if (again == 'y' || again == 'Y')
close = false;
else
close = true;
}
}
}