用c++写二十一点游戏的代码

以下是一个简单的 C++ 二十一点游戏代码，包括洗牌、发牌、计算点数和判断胜负等基本功能：

#include <iostream>
#include <cstdlib>
#include <ctime>
#include <vector>

using namespace std;

// 牌面大小
enum Rank {
    ACE = 1, TWO, THREE, FOUR, FIVE, SIX, SEVEN, EIGHT, NINE, TEN, JACK, QUEEN, KING
};

// 牌的花色
enum Suit {
    CLUBS, DIAMONDS, HEARTS, SPADES
};

// 牌结构体
struct Card {
    Rank rank;
    Suit suit;
};

// 生成一副新牌并洗牌
void shuffle(vector<Card>& deck) {
    deck.clear();
    for (int s = CLUBS; s <= SPADES; ++s) {
        for (int r = ACE; r <= KING; ++r) {
            deck.push_back({ static_cast<Rank>(r), static_cast<Suit>(s) });
        }
    }
    srand(time(NULL));
    for (size_t i = 0; i < deck.size(); ++i) {
        size_t j = rand() % deck.size();
        swap(deck[i], deck[j]);
    }
}

// 计算一张牌的点数
int getCardValue(const Card& card) {
    switch (card.rank) {
    case ACE:
        return 1;
    case TWO:
    case THREE:
    case FOUR:
    case FIVE:
    case SIX:
    case SEVEN:
    case EIGHT:
    case NINE:
        return card.rank;
    case TEN:
    case JACK:
    case QUEEN:
    case KING:
        return 10;
    default:
        return 0;
    }
}

// 计算一手牌的点数，如果牌中有 ACE，尽量使其作为 11 点计算，否则作为 1 点计算
int getHandValue(const vector<Card>& hand) {
    int numAces = 0;
    int value = 0;
    for (const auto& card : hand) {
        int cardValue = getCardValue(card);
        if (cardValue == 1) {
            ++numAces;
        }
        value += cardValue;
    }
    while (numAces > 0 && value + 10 <= 21) {
        value += 10;
        --numAces;
    }
    return value;
}

int main() {
    vector<Card> deck;
    shuffle(deck);

    vector<Card> playerHand, dealerHand;
    playerHand.push_back(deck.back());
    deck.pop_back();
    dealerHand.push_back(deck.back());
    deck.pop_back();
    playerHand.push_back(deck.back());
    deck.pop_back();

    cout << "你的牌是：" << endl;
    for (const auto& card : playerHand) {
        cout << static_cast<int>(card.rank) << " ";
    }
    cout << endl;

    cout << "庄家的牌是：" << endl;
    cout << static_cast<int>(dealerHand[0].rank) << " ?" << endl;

    while (true) {
        int playerValue = getHandValue(playerHand);
        if (playerValue == 21) {
            cout << "你赢了！" << endl;
            break;
        } else if (playerValue > 21) {
            cout << "你输了！" << endl;
            break;
        } else {
            cout << "你的点数是 " << playerValue << "，是否继续要牌？(y/n)" << endl;
            char choice;
            cin >> choice;
            if (choice == 'y') {
                playerHand.push_back(deck.back());
                deck.pop_back();
            } else {
                cout << "你停止要牌，庄家开始抽牌。" << endl;
                break;
            }
        }
    }

    while (true) {
        int dealerValue = getHandValue(dealerHand);
        if (dealerValue >= 17) {
            cout << "庄家的牌是：" << endl;
            for (const auto& card : dealerHand) {
                cout << static_cast<int>(card.rank) << " ";
            }
            cout << endl;
            if (dealerValue > 21) {
                cout << "庄家输了！" << endl;
            } else {
                int playerValue = getHandValue(playerHand);
                if (dealerValue > playerValue) {
                    cout << "庄家赢了！" << endl;
                } else if (dealerValue < playerValue) {
                    cout << "你赢了！" << endl;
                } else {
                    cout << "平局！" << endl;
                }
            }
            break;
        } else {
            dealerHand.push_back(deck.back());
            cout << "庄家抽了一张牌。" << endl;
            deck.pop_back();
        }
    }

    return 0;
}

这个代码只是一个简单的演示，还有很多细节需要注意，比如牌的数量、胜负规则、Ace 的计算方式等等。