C++ Primer Plus（第六版）第16章 string类和标准模板库

str1.cpp 

// str1.cpp -- introducing the string class
#include 
#include 
// using string constructors

int main()
{
	using namespace std;
	string one("Lottery Winner!");     // ctor #1
	cout << one << endl;               // overloaded <<
	string two(20, '$');               // ctor #2
	cout << two << endl;
	string three(one);                 // ctor #3
	cout << three << endl;
	one += " Oops!";                   // overloaded +=
	cout << one << endl;
	two = "Sorry! That was ";
	three[0] = 'P';
	string four;                       // ctor #4
	four = two + three;                // overloaded +, =
	cout << four << endl;
	char alls[] = "All's well that ends well";
	string five(alls, 20);              // ctor #5
	cout << five << "!\n";
	string six(alls + 6, alls + 10);     // ctor #6
	cout << six << ", ";
	string seven(&five[6], &five[10]); // ctor #6 again
	cout << seven << "...\n";
	string eight(four, 7, 16);         // ctor #7
    //将four的第八个字符(位置7)开始，将16个字符复制到eight中
	cout << eight << " in motion!" << endl;
	// std::cin.get();
	return 0;
}

执行结果：

Lottery Winner!
$$$$$$$$$$$$$$$$$$$$
Lottery Winner!
Lottery Winner! Oops!
Sorry! That was Pottery Winner!
All's well that ends!
well, well...
That was Pottery in motion!

 strfile.cpp

// strfile.cpp -- read strings from a file
#include 
#include 
#include 
#include 
int main()
{
	using namespace std;
	ifstream fin;
	fin.open("tobuy.txt");
	if (fin.is_open() == false)
	{
		cerr << "Can't open file. Bye.\n";
		exit(EXIT_FAILURE);
	}
	string item;
	int count = 0;

	getline(fin, item, ':');
	while (fin)  // while input is good
	{
		++count;
		cout << count << ": " << item << endl;
		getline(fin, item, ':');
	}
	cout << "Done\n";
	fin.close();
	// std::cin.get();
	// std::cin.get();
	return 0;
}

 tobuy.txt

sardines:chocolate ice cream:pop corn:leeks:
cottage cheese;olive oil:butter:tofu:

hangman.cpp 

// hangman.cpp -- some string methods
#include 
#include 
#include 
#include 
#include 
using std::string;
const int NUM = 26;
const string wordlist[NUM] = { "apiary", "beetle", "cereal",
	"danger", "ensign", "florid", "garage", "health", "insult",
	"jackal", "keeper", "loaner", "manage", "nonce", "onset",
	"plaid", "quilt", "remote", "stolid", "train", "useful",
	"valid", "whence", "xenon", "yearn", "zippy" };

int main()
{
	using std::cout;
	using std::cin;
	using std::tolower;
	using std::endl;

	std::srand(std::time(0));
	char play;
	cout << "Will you play a word game?  ";
	cin >> play;
	play = tolower(play);
	while (play == 'y')
	{
		string target = wordlist[std::rand() % NUM];
		int length = target.length();
		string attempt(length, '-');
		string badchars;
		int guesses = 6;
		cout << "Guess my secret word. It has " << length
			<< " letters, and you guess\n"
			<< "one letter at a time. You get " << guesses
			<< " wrong guesses.\n";
		cout << "Your word: " << attempt << endl;
		while (guesses > 0 && attempt != target)
		{
			char letter;
			cout << "Guess a letter: ";
			cin >> letter;
			if (badchars.find(letter) != string::npos
				|| attempt.find(letter) != string::npos)
			{
				cout << "You already guessed that. Try again.\n";
				continue;
			}
			int loc = target.find(letter);
			if (loc == string::npos)
			{
				cout << "Oh, bad guess!\n";
				--guesses;
				badchars += letter; // add to string
			}
			else
			{
				cout << "Good guess!\n";
				attempt[loc] = letter;
				// check if letter appears again
				loc = target.find(letter, loc + 1);
				while (loc != string::npos)
				{
					attempt[loc] = letter;
					loc = target.find(letter, loc + 1);
				}
			}
			cout << "Your word: " << attempt << endl;
			if (attempt != target)
			{
				if (badchars.length() > 0)
					cout << "Bad choices: " << badchars << endl;
				cout << guesses << " bad guesses left\n";
			}
		}
		if (guesses > 0)
			cout << "That's right!\n";
		else
			cout << "Sorry, the word is " << target << ".\n";

		cout << "Will you play another?  ";
		cin >> play;
		play = tolower(play);
	}

	cout << "Bye\n";

	return 0;
}

 执行结果：

1: sardines
2: chocolate ice cream
3: pop corn
4: leeks
5:
cottage cheese;olive oil
6: butter
7: tofu
Done

hangman.cpp 

// hangman.cpp -- some string methods
#include 
#include 
#include 
#include 
#include 
using std::string;
const int NUM = 26;
const string wordlist[NUM] = { "apiary", "beetle", "cereal",
	"danger", "ensign", "florid", "garage", "health", "insult",
	"jackal", "keeper", "loaner", "manage", "nonce", "onset",
	"plaid", "quilt", "remote", "stolid", "train", "useful",
	"valid", "whence", "xenon", "yearn", "zippy" };

int main()
{
	using std::cout;
	using std::cin;
	using std::tolower;
	using std::endl;

	std::srand(std::time(0));
	char play;
	cout << "Will you play a word game?  ";
	cin >> play;
	play = tolower(play);
	while (play == 'y')
	{
		string target = wordlist[std::rand() % NUM];
		int length = target.length();
		string attempt(length, '-');
		string badchars;
		int guesses = 6;
		cout << "Guess my secret word. It has " << length
			<< " letters, and you guess\n"
			<< "one letter at a time. You get " << guesses
			<< " wrong guesses.\n";
		cout << "Your word: " << attempt << endl;
		while (guesses > 0 && attempt != target)
		{
			char letter;
			cout << "Guess a letter: ";
			cin >> letter;
			if (badchars.find(letter) != string::npos
				|| attempt.find(letter) != string::npos)
			{
				cout << "You already guessed that. Try again.\n";
				continue;
			}
			int loc = target.find(letter);
			if (loc == string::npos)
			{
				cout << "Oh, bad guess!\n";
				--guesses;
				badchars += letter; // add to string
			}
			else
			{
				cout << "Good guess!\n";
				attempt[loc] = letter;
				// check if letter appears again
				loc = target.find(letter, loc + 1);
				while (loc != string::npos)
				{
					attempt[loc] = letter;
					loc = target.find(letter, loc + 1);
				}
			}
			cout << "Your word: " << attempt << endl;
			if (attempt != target)
			{
				if (badchars.length() > 0)
					cout << "Bad choices: " << badchars << endl;
				cout << guesses << " bad guesses left\n";
			}
		}
		if (guesses > 0)
			cout << "That's right!\n";
		else
			cout << "Sorry, the word is " << target << ".\n";

		cout << "Will you play another?  ";
		cin >> play;
		play = tolower(play);
	}

	cout << "Bye\n";

	return 0;
}

执行结果：

Will you play a word game?  y
Guess my secret word. It has 6 letters, and you guess
one letter at a time. You get 6 wrong guesses.
Your word: ------
Guess a letter: e
Good guess!
Your word: -ee-e-
6 bad guesses left
Guess a letter: l
Oh, bad guess!
Your word: -ee-e-
Bad choices: l
5 bad guesses left
Guess a letter: g
Oh, bad guess!
Your word: -ee-e-
Bad choices: lg
4 bad guesses left
Guess a letter: a
Oh, bad guess!
Your word: -ee-e-
Bad choices: lga
3 bad guesses left
Guess a letter: v
Oh, bad guess!
Your word: -ee-e-
Bad choices: lgav
2 bad guesses left
Guess a letter: l
You already guessed that. Try again.
Guess a letter: p
Good guess!
Your word: -eepe-
Bad choices: lgav
2 bad guesses left
Guess a letter: p
You already guessed that. Try again.
Guess a letter: k
Good guess!
Your word: keepe-
Bad choices: lgav
2 bad guesses left
Guess a letter: c
Oh, bad guess!
Your word: keepe-
Bad choices: lgavc
1 bad guesses left
Guess a letter: r
Good guess!
Your word: keeper
That's right!
Will you play another?  n
Bye

Guess a letter: o
Oh, bad guess!
Your word: ------
Bad choices: gno
3 bad guesses left
Guess a letter: e
Oh, bad guess!
Your word: ------
Bad choices: gnoe
2 bad guesses left
Guess a letter: p
Good guess!
Your word: -p----
Bad choices: gnoe
2 bad guesses left
Guess a letter: a
Good guess!
Your word: ap-a--
Bad choices: gnoe
2 bad guesses left
Guess a letter: i
Good guess!
Your word: apia--
Bad choices: gnoe
2 bad guesses left
Guess a letter: r
Good guess!
Your word: apiar-
Bad choices: gnoe
2 bad guesses left
Guess a letter: y
Good guess!
Your word: apiary
That's right!
Will you play another?  n
Bye

str2.cpp 

// str2.cpp -- capacity() and reserve()
#include 
#include 
int main()
{
	using namespace std;
	string empty;
	string small = "bit";
	string larger = "Elephants are a girl's best friend";
	cout << "Sizes:\n";
	cout << "\tempty: " << empty.size() << endl;
	cout << "\tsmall: " << small.size() << endl;
	cout << "\tlarger: " << larger.size() << endl;
	cout << "Capacities:\n";
	cout << "\tempty: " << empty.capacity() << endl;
	cout << "\tsmall: " << small.capacity() << endl;
	cout << "\tlarger: " << larger.capacity() << endl;
	empty.reserve(50);
	cout << "Capacity after empty.reserve(50): "
		<< empty.capacity() << endl;
	// cin.get();
	return 0;
}

执行结果：

Sizes:
        empty: 0
        small: 3
        larger: 34
Capacities:
        empty: 15
        small: 15
        larger: 47
Capacity after empty.reserve(50): 63

smrtptrs.cpp 

// smrtptrs.cpp -- using three kinds of smart pointers
#include 
#include 
#include 

class Report
{
private:
	std::string str;
public:
	Report(const std::string s) : str(s) { std::cout << "Object created!\n"; }
	~Report() { std::cout << "Object deleted!\n"; }
	void comment() const { std::cout << str << "\n"; }
};

int main()
{
	{
		std::auto_ptr ps(new Report("using auto_ptr"));
		ps->comment();   // use -> to invoke a member function
	}
	{
		std::shared_ptr ps(new Report("using shared_ptr"));
		ps->comment();
	}
	{
		std::unique_ptr ps(new Report("using unique_ptr"));
		ps->comment();
	}
	// std::cin.get();  
	return 0;
}

执行结果：

Object created!
using auto_ptr
Object deleted!
Object created!
using shared_ptr
Object deleted!
Object created!
using unique_ptr
Object deleted!

fowl.cpp 

// fowl.cpp  -- auto_ptr a poor choice
#include 
#include 
#include 

int main()
{
	using namespace std;
	auto_ptr films[5] =
	{
		auto_ptr(new string("Fowl Balls")),
		auto_ptr(new string("Duck Walks")),
		auto_ptr(new string("Chicken Runs")),
		auto_ptr(new string("Turkey Errors")),
		auto_ptr(new string("Goose Eggs"))
	};
	auto_ptr pwin;
	pwin = films[2];   // films[2] loses ownership

	cout << "The nominees for best avian baseball film are\n";
	for (int i = 0; i < 5; i++)
		cout << *films[i] << endl;
	cout << "The winner is " << *pwin << "!\n";
	// cin.get();
	return 0;
}

执行结果： 

The nominees for best avian baseball film are
Fowl Balls
Duck Walks

fow2.cpp  

将auto_ptr修改为shared_ptr得到的结果如下所示：

// fow2.cpp  -- auto_ptr a poor choice
#include 
#include 
#include 

int main()
{
	using namespace std;
	shared_ptr films[5] =
	{
		auto_ptr(new string("Fowl Balls")),
		auto_ptr(new string("Duck Walks")),
		auto_ptr(new string("Chicken Runs")),
		auto_ptr(new string("Turkey Errors")),
		auto_ptr(new string("Goose Eggs"))
	};
	shared_ptr pwin;
	pwin = films[2];   // films[2] loses ownership

	cout << "The nominees for best avian baseball film are\n";
	for (int i = 0; i < 5; i++)
		cout << *films[i] << endl;
	cout << "The winner is " << *pwin << "!\n";
	// cin.get();
	return 0;
}

执行结果：

The nominees for best avian baseball film are
Fowl Balls
Duck Walks
Chicken Runs
Turkey Errors
Goose Eggs
The winner is Chicken Runs!

vect1.cpp 

// vect1.cpp -- introducing the vector template
#include 
#include 
#include 

const int NUM = 5;
int main()
{
	using std::vector;
	using std::string;
	using std::cin;
	using std::cout;
	using std::endl;

	vector ratings(NUM);
	vector titles(NUM);
	cout << "You will do exactly as told. You will enter\n"
		<< NUM << " book titles and your ratings (0-10).\n";
	int i;
	for (i = 0; i < NUM; i++)
	{
		cout << "Enter title #" << i + 1 << ": ";
		getline(cin, titles[i]);
		cout << "Enter your rating (0-10): ";
		cin >> ratings[i];
		cin.get();
	}
	cout << "Thank you. You entered the following:\n"
		<< "Rating\tBook\n";
	for (i = 0; i < NUM; i++)
	{
		cout << ratings[i] << "\t" << titles[i] << endl;
	}
	// cin.get();

	return 0;
}

执行结果： 

You will do exactly as told. You will enter
5 book titles and your ratings (0-10).
Enter title #1: The Cat Who Knew C++
Enter your rating (0-10): 6
Enter title #2:  Felonious Felines
Enter your rating (0-10): 4
Enter title #3: Warlords of Wonk
Enter your rating (0-10): 3
Enter title #4:  Don't Touch That Metaphor
Enter your rating (0-10): 5
Enter title #5: Panic Oriented Programming
Enter your rating (0-10): 8
Thank you. You entered the following:
Rating  Book
6       The Cat Who Knew C++
4        Felonious Felines
3       Warlords of Wonk
5        Don't Touch That Metaphor
8       Panic Oriented Programming

 vect2.cpp

// vect2.cpp -- methods and iterators
#include 
#include 
#include 

struct Review {
	std::string title;
	int rating;
};
bool FillReview(Review & rr);
void ShowReview(const Review & rr);

int main()
{
	using std::cout;
	using std::vector;
	vector books;
	Review temp;
	while (FillReview(temp))
		books.push_back(temp);
	int num = books.size();
	if (num > 0)
	{
		cout << "Thank you. You entered the following:\n"
			<< "Rating\tBook\n";
		for (int i = 0; i < num; i++)
			ShowReview(books[i]);
		cout << "Reprising:\n"
			<< "Rating\tBook\n";
		vector::iterator pr;
		for (pr = books.begin(); pr != books.end(); pr++)
			ShowReview(*pr);
		vector  oldlist(books);     // copy constructor used
		if (num > 3)
		{
			// remove 2 items
			books.erase(books.begin() + 1, books.begin() + 3);//移除第二项和第四项
			cout << "After erasure:\n";
			for (pr = books.begin(); pr != books.end(); pr++)
				ShowReview(*pr);
			// insert 1 item
			books.insert(books.begin(), oldlist.begin() + 1,
				oldlist.begin() + 2);//[1,2)在开始的位置处插入第二项内容
			cout << "After insertion:\n";
			for (pr = books.begin(); pr != books.end(); pr++)
				ShowReview(*pr);
		}
		books.swap(oldlist);
		cout << "Swapping oldlist with books:\n";
		for (pr = books.begin(); pr != books.end(); pr++)
			ShowReview(*pr);
	}
	else
		cout << "Nothing entered, nothing gained.\n";
	// std::cin.get();
	return 0;
}

bool FillReview(Review & rr)
{
	std::cout << "Enter book title (quit to quit): ";
	std::getline(std::cin, rr.title);
	if (rr.title == "quit")
		return false;
	std::cout << "Enter book rating: ";
	std::cin >> rr.rating;
	if (!std::cin)
		return false;
	// get rid of rest of input line
	while (std::cin.get() != '\n')
		continue;
	return true;
}

void ShowReview(const Review & rr)
{
	std::cout << rr.rating << "\t" << rr.title << std::endl;
}

执行结果：

Enter book title (quit to quit): The Cat Who Knew C++
Enter book rating: 5
Enter book title (quit to quit): Candid Canines
Enter book rating: 7
Enter book title (quit to quit): Warriors of Wonk
Enter book rating: 4
Enter book title (quit to quit): Quantum Manners
Enter book rating: 8
Enter book title (quit to quit): quit
Thank you. You entered the following:
Rating  Book
5       The Cat Who Knew C++
7       Candid Canines
4       Warriors of Wonk
8       Quantum Manners
Reprising:
Rating  Book
5       The Cat Who Knew C++
7       Candid Canines
4       Warriors of Wonk
8       Quantum Manners
After erasure:
5       The Cat Who Knew C++
8       Quantum Manners
After insertion:
7       Candid Canines
5       The Cat Who Knew C++
8       Quantum Manners
Swapping oldlist with books:
5       The Cat Who Knew C++
7       Candid Canines
4       Warriors of Wonk
8       Quantum Manners

vect3.cpp 

// vect3.cpp -- using STL functions
#include 
#include 
#include 
#include 

struct Review {
	std::string title;
	int rating;
};

bool operator<(const Review & r1, const Review & r2);
bool worseThan(const Review & r1, const Review & r2);
bool FillReview(Review & rr);
void ShowReview(const Review & rr);
int main()
{
	using namespace std;

	vector books;
	Review temp;
	while (FillReview(temp))
		books.push_back(temp);
	if (books.size() > 0)
	{
		cout << "Thank you. You entered the following "
			<< books.size() << " ratings:\n"
			<< "Rating\tBook\n";
		for_each(books.begin(), books.end(), ShowReview);

		sort(books.begin(), books.end());
		cout << "Sorted by title:\nRating\tBook\n";
		for_each(books.begin(), books.end(), ShowReview);

		sort(books.begin(), books.end(), worseThan);
		cout << "Sorted by rating:\nRating\tBook\n";
		for_each(books.begin(), books.end(), ShowReview);

		random_shuffle(books.begin(), books.end());
		cout << "After shuffling:\nRating\tBook\n";
		for_each(books.begin(), books.end(), ShowReview);
	}
	else
		cout << "No entries. ";
	cout << "Bye.\n";
	// cin.get();
	return 0;
}

bool operator<(const Review & r1, const Review & r2)
{
	if (r1.title < r2.title)
		return true;
	else if (r1.title == r2.title && r1.rating < r2.rating)
		return true;
	else
		return false;
}

bool worseThan(const Review & r1, const Review & r2)
{
	if (r1.rating < r2.rating)
		return true;
	else
		return false;
}

bool FillReview(Review & rr)
{
	std::cout << "Enter book title (quit to quit): ";
	std::getline(std::cin, rr.title);
	if (rr.title == "quit")
		return false;
	std::cout << "Enter book rating: ";
	std::cin >> rr.rating;
	if (!std::cin)
		return false;
	// get rid of rest of input line
	while (std::cin.get() != '\n')
		continue;
	return true;
}

void ShowReview(const Review & rr)
{
	std::cout << rr.rating << "\t" << rr.title << std::endl;
}

执行结果：

Enter book title (quit to quit): The Cat Who Can Teach You Weight Loss
Enter book rating: 8
Enter book title (quit to quit): The Dogs of Dharma
Enter book rating: 6
Enter book title (quit to quit): The Wimps of Wonk
Enter book rating: 3
Enter book title (quit to quit): Farewell and Delete
Enter book rating: 7
Enter book title (quit to quit): quit
Thank you. You entered the following 4 ratings:
Rating  Book
8       The Cat Who Can Teach You Weight Loss
6       The Dogs of Dharma
3       The Wimps of Wonk
7       Farewell and Delete
Sorted by title:
Rating  Book
7       Farewell and Delete
8       The Cat Who Can Teach You Weight Loss
6       The Dogs of Dharma
3       The Wimps of Wonk
Sorted by rating:
Rating  Book
3       The Wimps of Wonk
6       The Dogs of Dharma
7       Farewell and Delete
8       The Cat Who Can Teach You Weight Loss
After shuffling:
Rating  Book
3       The Wimps of Wonk
6       The Dogs of Dharma
8       The Cat Who Can Teach You Weight Loss
7       Farewell and Delete
Bye.

copyit.cpp 

// copyit.cpp -- copy() and iterators
#include 
#include 
#include 

int main()
{
	using namespace std;

	int casts[10] = { 6, 7, 2, 9 ,4 , 11, 8, 7, 10, 5 };
	vector dice(10);
	// copy from array to vector
	copy(casts, casts + 10, dice.begin());
	cout << "Let the dice be cast!\n";
	// create an ostream iterator
	ostream_iterator out_iter(cout, " ");
	// copy from vector to output
	copy(dice.begin(), dice.end(), out_iter);
	cout << endl;
	cout << "Implicit use of reverse iterator.\n";
	copy(dice.rbegin(), dice.rend(), out_iter);
	cout << endl;
	cout << "Explicit use of reverse iterator.\n";
	// vector::reverse_iterator ri;  // use if auto doesn't work
	for (auto ri = dice.rbegin(); ri != dice.rend(); ++ri)
		cout << *ri << ' ';
	cout << endl;
	// cin.get();
	return 0;
}

执行结果:

6 7 2 9 4 11 8 7 10 5
Implicit use of reverse iterator.
5 10 7 8 11 4 9 2 7 6
Explicit use of reverse iterator.
5 10 7 8 11 4 9 2 7 6

inserts.cpp 

// inserts.cpp -- copy() and insert iterators
#include 
#include 
#include 
#include 
#include 

void output(const std::string & s) { std::cout << s << " "; }

int main()
{
	using namespace std;
	string s1[4] = { "fine", "fish", "fashion", "fate" };
	string s2[2] = { "busy", "bats" };
	string s3[2] = { "silly", "singers" };
	vector words(4);
	copy(s1, s1 + 4, words.begin());
	for_each(words.begin(), words.end(), output);
	cout << endl;

	// construct anonymous back_insert_iterator object
	copy(s2, s2 + 2, back_insert_iterator >(words));
	//back_insert_iterator只能用于允许在尾部快速插入的容器
	//front_insert_iterator只能用于允许在起始位置做时间固定插入的容器类型
	for_each(words.begin(), words.end(), output);
	cout << endl;

	// construct anonymous insert_iterator object
	copy(s3, s3 + 2, insert_iterator >(words, words.begin()));
	//在其实位置插入s3的内容
	for_each(words.begin(), words.end(), output);
	cout << endl;
	// cin.get();
	return 0;
}

执行结果： 

fine fish fashion fate
fine fish fashion fate busy bats
silly singers fine fish fashion fate busy bats

list.cpp 

// list.cpp -- using a list
#include 
#include 
#include 
#include 

void outint(int n) { std::cout << n << " "; }

int main()
{
	using namespace std;
	list one(5, 2); // list of 5 2s
	int stuff[5] = { 1,2,4,8, 6 };
	list two;
	two.insert(two.begin(), stuff, stuff + 5);
	int more[6] = { 6, 4, 2, 4, 6, 5 };
	list three(two);
	three.insert(three.end(), more, more + 6);

	cout << "List one: ";
	for_each(one.begin(), one.end(), outint);
	cout << endl << "List two: ";
	for_each(two.begin(), two.end(), outint);
	cout << endl << "List three: ";
	for_each(three.begin(), three.end(), outint);
	three.remove(2);
	cout << endl << "List three minus 2s: ";
	for_each(three.begin(), three.end(), outint);
	three.splice(three.begin(), one);
	cout << endl << "List three after splice: ";
	for_each(three.begin(), three.end(), outint);
	cout << endl << "List one: ";
	for_each(one.begin(), one.end(), outint);
	three.unique();
	cout << endl << "List three after unique: ";
	for_each(three.begin(), three.end(), outint);
	three.sort();
	three.unique();
	cout << endl << "List three after sort & unique: ";
	for_each(three.begin(), three.end(), outint);
	two.sort();
	three.merge(two);
	cout << endl << "Sorted two merged into three: ";
	for_each(three.begin(), three.end(), outint);
	cout << endl;
	// cin.get();

	return 0;
}

执行结果：

List one: 2 2 2 2 2
List two: 1 2 4 8 6
List three: 1 2 4 8 6 6 4 2 4 6 5
List three minus 2s: 1 4 8 6 6 4 4 6 5
List three after splice: 2 2 2 2 2 1 4 8 6 6 4 4 6 5
List one:
List three after unique: 2 1 4 8 6 4 6 5
List three after sort & unique: 1 2 4 5 6 8
Sorted two merged into three: 1 1 2 2 4 4 5 6 6 8 8

setops.cpp  

// setops.cpp -- some set operations
#include 
#include 
#include 
#include 
#include 

int main()
{
	using namespace std;
	const int N = 6;
	string s1[N] = { "buffoon", "thinkers", "for", "heavy", "can", "for" };
	string s2[N] = { "metal", "any", "food", "elegant", "deliver","for" };

	set A(s1, s1 + N);
	set B(s2, s2 + N);

	ostream_iterator out(cout, " ");
	cout << "Set A: ";
	copy(A.begin(), A.end(), out);
	cout << endl;
	cout << "Set B: ";
	copy(B.begin(), B.end(), out);
	cout << endl;

	cout << "Union of A and B:\n";
	set_union(A.begin(), A.end(), B.begin(), B.end(), out);
	cout << endl;

	cout << "Intersection of A and B:\n";
	set_intersection(A.begin(), A.end(), B.begin(), B.end(), out);
	//set_intersection查找两个集合的交集
	cout << endl;

	cout << "Difference of A and B:\n";
	set_difference(A.begin(), A.end(), B.begin(), B.end(), out);
	//set_difference查找两个集合的差
	cout << endl;

	set C;
	cout << "Set C:\n";
	set_union(A.begin(), A.end(), B.begin(), B.end(),
		insert_iterator >(C, C.begin()));
	copy(C.begin(), C.end(), out);
	cout << endl;

	string s3("grungy");
	C.insert(s3);
	cout << "Set C after insertion:\n";
	copy(C.begin(), C.end(), out);
	cout << endl;

	cout << "Showing a range:\n";
	copy(C.lower_bound("ghost"), C.upper_bound("spook"), out);
	//lower_bound将键作为参数并返回一个迭代器，该迭代器指向集合中第一个不小于键参数的成员
	//upper_bound将键作为参数并返回一个迭代器，该迭代器指向集合中第一个大于键参数的成员
	cout << endl;
	// cin.get();
	return 0;
}

执行效果：

Set A: buffoon can for heavy thinkers
Set B: any deliver elegant food for metal
Union of A and B:
any buffoon can deliver elegant food for heavy metal thinkers
Intersection of A and B:
for
Difference of A and B:
buffoon can heavy thinkers
Set C:
any buffoon can deliver elegant food for heavy metal thinkers
Set C after insertion:
any buffoon can deliver elegant food for grungy heavy metal thinkers
Showing a range:
grungy heavy metal

ERROR:

“std::pair>>,std::_Tree_iterator>>>”后面接“auto”是非法的(是否忘记了“;”?)    

 去掉auto：

multmap.cpp 

// multmap.cpp -- use a multimap
#include 
#include 
#include 

 执行结果：

Number of cities with area code 415: 2
Number of cities with area code 718: 2
Number of cities with area code 510: 2
Area Code   City
    415     San Francisco
    415     San Rafael
    510     Oakland
    510     Berkeley
    718     Brooklyn
    718     Staten Island
Cities with area code 718:
Brooklyn
Staten Island

functor.cpp 

// functor.cpp -- using a functor
#include 
#include 
#include 
#include 

template  // functor class defines operator()()
class TooBig
{
private:
	T cutoff;
public:
	TooBig(const T & t) : cutoff(t) {}
	bool operator()(const T & v) { return v > cutoff; }
};

void outint(int n) { std::cout << n << " "; }

int main()
{
	using std::list;
	using std::cout;
	using std::endl;
	using std::for_each;
	using std::remove_if;

	TooBig f100(100); // limit = 100
	int vals[10] = { 50, 100, 90, 180, 60, 210, 415, 88, 188, 201 };
	list yadayada(vals, vals + 10); // range constructor
	list etcetera(vals, vals + 10);

	// C++0x can use the following instead
   //  list yadayada = {50, 100, 90, 180, 60, 210, 415, 88, 188, 201};
   //  list etcetera {50, 100, 90, 180, 60, 210, 415, 88, 188, 201};

	cout << "Original lists:\n";
	for_each(yadayada.begin(), yadayada.end(), outint);
	cout << endl;
	for_each(etcetera.begin(), etcetera.end(), outint);
	cout << endl;
	yadayada.remove_if(f100);               // use a named function object
	etcetera.remove_if(TooBig(200));   // construct a function object
	cout << "Trimmed lists:\n";
	for_each(yadayada.begin(), yadayada.end(), outint);
	cout << endl;
	for_each(etcetera.begin(), etcetera.end(), outint);
	cout << endl;
	// std::cin.get();
	return 0;
}

执行结果：

Original lists:
50 100 90 180 60 210 415 88 188 201
50 100 90 180 60 210 415 88 188 201
Trimmed lists:
50 100 90 60 88
50 100 90 180 60 88 188

funadap.cpp

// funadap.cpp -- using function adapters
#include 
#include 
#include 
#include 
#include 

void Show(double);
const int LIM = 6;
int main()
{
	using namespace std;
	double arr1[LIM] = { 28, 29, 30, 35, 38, 59 };
	double arr2[LIM] = { 63, 65, 69, 75, 80, 99 };
	vector gr8(arr1, arr1 + LIM);
	vector m8(arr2, arr2 + LIM);
	cout.setf(ios_base::fixed);
	cout.precision(1);
	cout << "gr8:\t";
	for_each(gr8.begin(), gr8.end(), Show);
	cout << endl;
	cout << "m8: \t";
	for_each(m8.begin(), m8.end(), Show);
	cout << endl;

	vector sum(LIM);
	transform(gr8.begin(), gr8.end(), m8.begin(), sum.begin(),
		plus());
	cout << "sum:\t";
	for_each(sum.begin(), sum.end(), Show);
	cout << endl;

	vector prod(LIM);
	transform(gr8.begin(), gr8.end(), prod.begin(),
		bind1st(multiplies(), 2.5));
	cout << "prod:\t";
	for_each(prod.begin(), prod.end(), Show);
	cout << endl;
	// cin.get();
	return 0;
}

void Show(double v)
{
	std::cout.width(6);
	std::cout << v << ' ';
}

执行效果： 

gr8:      28.0   29.0   30.0   35.0   38.0   59.0
m8:       63.0   65.0   69.0   75.0   80.0   99.0
sum:      91.0   94.0   99.0  110.0  118.0  158.0
prod:     70.0   72.5   75.0   87.5   95.0  147.5

strgstl.cpp 

// strgstl.cpp -- applying the STL to a string
#include 
#include 
#include 

int main()
{
	using namespace std;
	string letters;

	cout << "Enter the letter grouping (quit to quit): ";
	while (cin >> letters && letters != "quit")
	{
		cout << "Permutations of " << letters << endl;
		sort(letters.begin(), letters.end());
		cout << letters << endl;
		while (next_permutation(letters.begin(), letters.end()))
			cout << letters << endl;
		cout << "Enter next sequence (quit to quit): ";
	}
	cout << "Done.\n";
	// cin.get();
	// cin.get();
	return 0;
}

执行效果：

Enter the letter grouping (quit to quit): aw1
Permutations of aw1
1aw
1wa
a1w
aw1
w1a
wa1
Enter next sequence (quit to quit): all
Permutations of all
all
lal
lla
Enter next sequence (quit to quit): quit
Done.

listrmv.cpp 

// listrmv.cpp -- applying the STL to a string
#include 
#include 
#include 

void Show(int);
const int LIM = 10;
int main()
{
	using namespace std;
	int ar[LIM] = { 4, 5, 4, 2, 2, 3, 4, 8, 1, 4 };
	list la(ar, ar + LIM);
	list lb(la);

	cout << "Original list contents:\n\t";
	for_each(la.begin(), la.end(), Show);
	cout << endl;
	la.remove(4);
	cout << "After using the remove() method:\n";
	cout << "la:\t";
	for_each(la.begin(), la.end(), Show);
	cout << endl;
	list::iterator last;
	last = remove(lb.begin(), lb.end(), 4);
	cout << "After using the remove() function:\n";
	cout << "lb:\t";
	for_each(lb.begin(), lb.end(), Show);
	cout << endl;
	lb.erase(last, lb.end());
	cout << "After using the erase() method:\n";
	cout << "lb:\t";
	for_each(lb.begin(), lb.end(), Show);
	cout << endl;
	// cin.get();    
	return 0;
}

void Show(int v)
{
	std::cout << v << ' ';
}

执行结果：

Original list contents:
        4 5 4 2 2 3 4 8 1 4
After using the remove() method:
la:     5 2 2 3 8 1
After using the remove() function:
lb:     5 2 2 3 8 1 4 8 1 4
After using the erase() method:
lb:     5 2 2 3 8 1

usealgo.cpp 

//usealgo.cpp -- using several STL elements
#include 
#include 
#include 
#include 
#include 

执行结果：

Enter words (enter quit to quit):
The dog saw the cat and thought the cat fat
The cat thought the cat perfect
quit
You entered the following words:
The dog saw the cat and thought the cat fat The cat thought the cat perfect

Alphabetic list of words:
and cat dog fat perfect saw the thought

Word frequency:
and: 1
cat: 4
dog: 1
fat: 1
perfect: 1
saw: 1
the: 5
thought: 2

valvect.cpp 

// valvect.cpp -- comparing vector and valarray
#include 
#include 
#include 
#include 
int main()
{
	using namespace std;
	vector data;
	double temp;

	cout << "Enter numbers (<=0 to quit):\n";
	while (cin >> temp && temp > 0)
		data.push_back(temp);
	sort(data.begin(), data.end());
	int size = data.size();
	valarray numbers(size);
	int i;
	for (i = 0; i < size; i++)
		numbers[i] = data[i];
	valarray sq_rts(size);
	sq_rts = sqrt(numbers);
	valarray results(size);
	results = numbers + 2.0 * sq_rts;
	cout.setf(ios_base::fixed);
	cout.precision(4);
	for (i = 0; i < size; i++)
	{
		cout.width(8);
		cout << numbers[i] << ": ";
		cout.width(8);
		cout << results[i] << endl;
	}
	cout << "done\n";
	// cin.get();
	// cin.get();

	return 0;
}

执行结果：

Enter numbers (<=0 to quit):
3.3 1.8 5.2 10 14.4 21.6 26.9 0
  1.8000:   4.4833
  3.3000:   6.9332
  5.2000:   9.7607
 10.0000:  16.3246
 14.4000:  21.9895
 21.6000:  30.8952
 26.9000:  37.2730
done

vslice.cpp 

// vslice.cpp -- using valarray slices
#include 
#include 
#include 

const int SIZE = 12;
typedef std::valarray vint;     // simplify declarations
void show(const vint & v, int cols);
int main()
{
	using std::slice;                // from 
	using std::cout;
	vint valint(SIZE);               // think of as 4 rows of 3

	int i;
	for (i = 0; i < SIZE; ++i)
		valint[i] = std::rand() % 10;
	cout << "Original array:\n";
	show(valint, 3);                 // show in 3 columns
	vint vcol(valint[slice(1, 4, 3)]); // extract 2nd column
	cout << "Second column:\n";
	show(vcol, 1);                   // show in 1 column
	vint vrow(valint[slice(3, 3, 1)]); // extract 2nd row
	cout << "Second row:\n";
	show(vrow, 3);
	valint[slice(2, 4, 3)] = 10;      // assign to 2nd column
	cout << "Set last column to 10:\n";
	show(valint, 3);
	cout << "Set first column to sum of next two:\n";
	// + not defined for slices, so convert to valarray
	valint[slice(0, 4, 3)] = vint(valint[slice(1, 4, 3)])
		+ vint(valint[slice(2, 4, 3)]);
	show(valint, 3);
	// std::cin.get();
	return 0;
}

void show(const vint & v, int cols)
{
	using std::cout;
	using std::endl;

	int lim = v.size();
	for (int i = 0; i < lim; ++i)
	{
		cout.width(3);
		cout << v[i];
		if (i % cols == cols - 1)
			cout << endl;
		else
			cout << ' ';
	}
	if (lim % cols != 0)
		cout << endl;
}

执行结果：

Original array:
  1   7   4
  0   9   4
  8   8   2
  4   5   5
Second column:
  7
  9
  8
  5
Second row:
  0   9   4
Set last column to 10:
  1   7  10
  0   9  10
  8   8  10
  4   5  10
Set first column to sum of next two:
 17   7  10
 19   9  10
 18   8  10
 15   5  10

ilist.cpp 

// ilist.cpp  -- use initializer_list
#include 
#include 

double sum(std::initializer_list il);
double average(const std::initializer_list & ril);

int main()
{
	using std::cout;

	cout << "List 1: sum = " << sum({ 2,3,4 })
		<< ", ave = " << average({ 2,3,4 }) << '\n';
	std::initializer_list dl = { 1.1, 2.2, 3.3, 4.4, 5.5 };
	cout << "List 2: sum = " << sum(dl)
		<< ", ave = " << average(dl) << '\n';
	dl = { 16.0, 25.0, 36.0, 40.0, 64.0 };
	cout << "List 3: sum = " << sum(dl)
		<< ", ave = " << average(dl) << '\n';
	// std::cin.get();
	return 0;
}

double sum(std::initializer_list il)
{
	double tot = 0;
	for (auto p = il.begin(); p != il.end(); p++)
		tot += *p;
	return tot;
}

double average(const std::initializer_list & ril)
{
	double tot = 0;
	int n = ril.size();
	double ave = 0.0;

	if (n > 0)
	{
		for (auto p = ril.begin(); p != ril.end(); p++)
			tot += *p;
		ave = tot / n;
	}
	return ave;
}

执行结果：

List 1: sum = 9, ave = 3
List 2: sum = 16.5, ave = 3.3
List 3: sum = 181, ave = 36.2