C++ Primer Pluse_6_课后题

#include <iostream>
#include <cctype>
#include <array>
#include <string>
#include <cstring>
#include <fstream>
#include <cstdlib>

using namespace std;

int t6_1()
{

	char ch;

	cout << "Enter text for analysis, and type # to terminate input.
";
	cin.get(ch);
	while (ch != '@')
	{
		if (isdigit(ch))
		{
			cin.get(ch);
			continue;
		}
		else if (isupper(ch))
		{
			ch = tolower(ch);
		}
		else if (islower(ch))
		{
			ch = toupper(ch);
		}
		cout << ch;

		cin.get(ch);
	}
	cout << endl;
	system("pause");
	return 0;
}

const int MaxSize = 10;
int t6_2()
{
	array<double, MaxSize>donations = { 0 };

	cout << "input the donations:
";
	
	cout << "donation#1:";
	int i = 0;
	while (i <MaxSize && cin >> donations[i])
	{
		if (++i <MaxSize)
		{
			cout << "donation#" << i + 1<<":";
		}
	}

	double total = 0;
	double average = 0;

	for (int j = 0; j < i; j++)
	{
		total += donations[j];
	}
	if (i==0)
	{
		cout << "No donations.
";
	}
	else
	{
		average = total / i;
		cout << "Average is " << average << endl;
		cout << "Bigger than average: ";
		for (int j = 0; j < i; j++)
		{

			if (donations[j] > average)
			{
				cout << donations[j] << " ";
			}
		}
	}

	system("pause");
	return 0;
}

int t6_3()
{
	char ch;

	cout << "Please enter aone of the following choices:
";
	cout << "c) carnivore			 p) pianist
";
	cout << "t) tree				 g) game
";
	cin.get(ch).get();

	while (true)
	{
		switch (ch)
		{
		case 'c': cout << "A map is a carnivore.
"; break;
		case 'p': cout << "A map is a pianist.
"; break;
		case 't': cout << "A map is a tree.
"; break;
		case 'g': cout << "A map is a game.
"; break;
		default:
			cout << "Please enter a c, p, t, g:"; 
			break;
		}
		cin.get(ch).get();
	}

	system("pause");
	return 0;
}
const int strsize = 20;
typedef struct Bop{
	char fullname[strsize];
	char title[strsize];
	char bopname[strsize];
	int preference;
}bop;
int t6_4()
{
	bop b1 = { "bopp1", "title1", "bop1", 1 };
	bop b2 = { "bopp2", "title2", "bop2", 0 };
	bop b3 = { "bopp3", "title3", "bop3", 2 };

	cout << "BOP report.
";
	cout << "a.display by name.			 b.display by title.
";
	cout << "c.display by bopname.		 d.display by preference.
";
	cout << "q.quit.
";
	cout << "Enter your choice:";
	char ch;
	cin.get(ch).get();
	while (ch != 'q')
	{
		switch (ch)
		{
		case 'a':
			cout << b1.fullname << endl;
			cout << b2.fullname << endl;
			cout << b3.fullname << endl;
			break;
		case 'b':
			cout << b1.title << endl;
			cout << b2.title << endl;
			cout << b3.title << endl;
			break;
		case 'c':
			cout << b1.bopname << endl;
			cout << b2.bopname << endl;
			cout << b3.bopname << endl;
			break;
		case 'd':
			if (b1.preference== 0)
			{
				cout << b1.fullname << endl;
			}
			else if (b1.preference ==1)
			{
				cout << b1.title << endl;
			}
			else
			{
				cout << b1.bopname << endl;
			}

			if (b2.preference == 0)
			{
				cout << b2.fullname << endl;
			}
			else if (b2.preference == 1)
			{
				cout << b2.title << endl;
			}
			else
			{
				cout << b2.bopname << endl;
			}

			if (b3.preference == 0)
			{
				cout << b3.fullname << endl;
			}
			else if (b3.preference == 1)
			{
				cout << b3.title << endl;
			}
			else
			{
				cout << b3.bopname << endl;
			}
			break;

		default: 
			cout << "Please input a a, b, c, d ,q:";
		}
		cin.get(ch).get();
	}
	cout << "Bye!";

	system("pause");
	return 0;
}

int t6_5()
{
	double wage = 0;
	double tax = 0;
	
	while (cin>>wage && wage >=0)
	{
		if (wage <= 5000)
		{
			tax = 0;
		}
		else if (wage > 5000 && wage <= 1500)
		{
			tax = 5000 * 0 + (wage - 5000)*0.1;
		}
		else if (wage > 1500 && wage <= 3500)
		{
			tax = 5000 * 0 + 10000 * 0.1 + (wage - 15000)*0.15;
		}
		else
		{
			tax = 5000 * 0 + 10000 * 0.1 + 20000 * 0.15 + (wage - 35000)*0.2;
		}

		cout << "tax = " << tax << endl;
	}

	system("pause");
	return 0;
}

typedef struct Donor
{
	string name;
	double money;
}donor;
int t6_6()
{
	int donors = 0;

	cout << "Enter the number of donors.
";
	cin >> donors;
	cin.get();
	donor *donorSet = new donor[donors];

	for (int i = 0; i < donors; i++)
	{
		cout << "Enter donor#" << i + 1 << ":
";
		getline(cin, donorSet[i].name);
		cin >> donorSet[i].money;
		cin.get();
	}
	
	cout << "
Grand Patrons:
";
	int flag = 0;
	for (int i = 0; i < donors; i++)
	{
		if (donorSet[i].money > 10000)
		{
			cout << donorSet[i].name << endl;
			flag = 1;
		}
	}
	if (flag == 0)
	{
		cout << "None.
";
	}

	cout << "Patrons:
";
	flag = 0;
	for (int i = 0; i < donors; i++)
	{
		if (donorSet[i].money <= 10000)
		{
			cout << donorSet[i].name << endl;
			flag = 1;
		}
	}
	if (flag == 0)
	{
		cout << "None.
";
	}

	system("pause");
	return 0;
}

int t6_7()
{
	int vowelCount = 0;
	int consonantsCount = 0;
	char ch;

	cout << "Enter words (q to quit):
";
	cin.get(ch);
	while (ch != 'q')
	{
		if (isalpha(ch))
		{
			if (tolower(ch) == 'a' || tolower(ch) == 'e' || tolower(ch) == 'i' || tolower(ch) == 'o' || tolower(ch) == 'u')
			{
				vowelCount++;
			}
			else
				consonantsCount++;

			cin.get(ch);
			while (ch != ' '&& ch != '
')
			{
				cin.get(ch);
			}
		}
		else
			cin.get(ch);
	}

	cout << vowelCount << " words beginning with vowels.
";
	cout << consonantsCount << " words beginning with consonants.
";
	//system("pause");
	return 0;
}

const int SIZE = 60;
int test6_8()
{
	char filename[SIZE];
	ifstream inFile;
	cout << "Enter the name of the data file:";
	cin.getline(filename,SIZE);
	inFile.open(filename);

	if (!inFile.is_open())//failed to open file
	{
		cout << "Could not open the file.
";
		cout << "Program terminating.
";
		exit(EXIT_FAILURE);
	}

	char ch;
	int count = 0;
	
	inFile >> ch;
	while (inFile.good())
	{
		count++;
		inFile >> ch;
		cout << ch;
	}
	
	if (inFile.eof())
	{
		cout << "End of the file.
";
	}
	else if (inFile.fail())
	{
		cout << "Input terminated by data mismatch.
";
	}
	else
		cout << "Input terminated for unknown reason.
";

	inFile.close();

	cout << "file has " << count << "characters.
";

	return 0;
}

int test6_9()
{
	char filename[SIZE];
	ifstream inFile;
	cout << "Enter the file name: ";
	cin.getline(filename, SIZE);

	inFile.open(filename);
	if (!inFile.is_open())
	{
		cout << "File cannot be opened.
";
		cout << "Program terminating.
";
		exit(EXIT_FAILURE);
	}

	int donors = 0;

	cout << "Enter the number of donors.
";
	inFile >> donors;
	inFile.get();
	donor *donorSet = new donor[donors];

	for (int i = 0; i < donors; i++)
	{
		cout << "Enter donor#" << i + 1 << ":
";
		getline(inFile, donorSet[i].name);
		inFile >> donorSet[i].money;
		inFile.get();
	}
	
	if (inFile.eof())
	{
		cout << "file end.
";
	}
	else if (inFile.fail())
	{
		cout << "Input file terminated by mismatch.
";
	}
	else
		cout << "Input file terminated by unknown reasons.
";

	inFile.close();

	cout << "
Grand Patrons:
";
	int flag = 0;
	for (int i = 0; i < donors; i++)
	{
		if (donorSet[i].money > 10000)
		{
			cout << donorSet[i].name << endl;
			flag = 1;
		}
	}
	if (flag == 0)
	{
		cout << "None.
";
	}

	cout << "Patrons:
";
	flag = 0;
	for (int i = 0; i < donors; i++)
	{
		if (donorSet[i].money <= 10000)
		{
			cout << donorSet[i].name << endl;
			flag = 1;
		}
	}
	if (flag == 0)
	{
		cout << "None.
";
	}


	return 0;
}

int main()
{
	test6_9();
	system("pause");
	return 0;
}