C++ 数组、Vector 与容器：总结与章节测验

std::vector v{1, 2, 3}; // 列表初始化

std::vector v1{5};  // 1 个元素，值为 5
std::vector v2(5);  // 5 个元素，值初始化

std::vector v1{ 3, 8, 2, 5, 7, 8, 3 };
std::vector v2{ 5.5, 2.7, 3.3, 7.6, 1.2, 8.8, 6.6 };

#include <iostream>
#include <vector>
#include <string>
#include <algorithm>
#include <random>
#include <limits>

// ---------- Step 1: 词库 ----------
namespace WordList
{
    const std::vector<std::string_view> words {
        "mystery", "broccoli", "account", "almost",
        "spaghetti", "opinion", "beautiful", "distance", "luggage"
    };

    std::string pickRandomWord()
    {
        static std::mt19937 rng{ std::random_device{}() };
        std::uniform_int_distribution<std::size_t> dist(0, words.size() - 1);
        return std::string{ words[dist(rng)] };
    }
}

// ---------- Step 2~4: 游戏会话 ----------
class Session
{
public:
    explicit Session(const std::string& word)
        : m_word{ word }, m_display(word.size(), '_'),
          m_wrongGuessesLeft{ 6 }, m_guessed(26, false)
    {}

    void play()
    {
        std::cout << "Welcome to C++man (a variant of Hangman)\n"
                  << "To win: guess the word.  To lose: run out of pluses.\n\n";

        while (!gameOver())
        {
            display();
            char guess = getUserGuess();
            processGuess(guess);
        }

        displayFinal();
    }

private:
    bool gameOver() const
    {
        return m_wrongGuessesLeft == 0 || m_display == m_word;
    }

    void display() const
    {
        std::cout << "The word: " << m_display
                  << "   Wrong guesses: ";
        for (int i = 0; i < m_wrongGuessesLeft; ++i) std::cout << '+';
        for (char c : m_wrongLetters) std::cout << c;
        std::cout << "\n";
    }

    char getUserGuess()
    {
        while (true)
        {
            std::cout << "Enter your next letter: ";
            std::string input;
            std::getline(std::cin, input);

            if (input.size() != 1 || !std::isalpha(input[0]))
            {
                std::cout << "That wasn't a valid input.  Try again.\n";
                continue;
            }
            char c = std::tolower(input[0]);
            if (m_guessed[c - 'a'])
            {
                std::cout << "You already guessed that.  Try again.\n";
                continue;
            }
            return c;
        }
    }

    void processGuess(char ch)
    {
        m_guessed[ch - 'a'] = true;

        bool hit = false;
        for (std::size_t i = 0; i < m_word.size(); ++i)
            if (m_word[i] == ch)
            {
                m_display[i] = ch;
                hit = true;
            }

        if (hit)
            std::cout << "Yes, '" << ch << "' is in the word!\n";
        else
        {
            std::cout << "No, '" << ch << "' is not in the word!\n";
            --m_wrongGuessesLeft;
            m_wrongLetters.push_back(ch);
        }
    }

    void displayFinal() const
    {
        if (m_display == m_word)
            std::cout << "Congratulations, you won!  The word was: " << m_word << '\n';
        else
            std::cout << "You lost!  The word was: " << m_word << '\n';
    }

    const std::string m_word;
    std::string m_display;
    int m_wrongGuessesLeft;
    std::vector<bool> m_guessed;
    std::string m_wrongLetters;
};

// ---------- 主函数 ----------
int main()
{
    Session game{ WordList::pickRandomWord() };
    game.play();
    return 0;
}