初学者在玩石头、剪纸、玩游戏时需要帮助

Question

我们应该使用函数编写一个石头、剪子布的游戏。除了确定获胜者并展示这一点之外，我已经完成了所有工作。 “无效结果”是我遇到的问题。

目前，我可以选择石头剪刀布，让电脑显示用户的选择和电脑的选择。这是我当前的代码：

#include <iostream>
#include <ctime>
#include <cstdlib>
using namespace std;

int user(int);
int pc(int);
int result(int);
string userChoice, pcChoice;
int userNum, pcNum;
void result(int, int);

int main()
{
    user(userNum);
    pc(pcNum);
    
    cout << "You chose " << userChoice << endl << "They chose " << pcChoice;
    return 0;
    
    void result();
}

int user(int userNum)
{
    cout << "Choose rock, paper, or scissors: ";
    cin >> userChoice;
    
    if(userChoice == "rock")
    {
        userNum = 1;
    }
    else if(userChoice == "paper")
    {
        userNum = 2;
    }
    else if(userChoice == "scissors")
    {
        userNum = 3;
    }
    else
    {
        cout << "Input invalid. Run again and enter rock, paper, or scissors." << endl;
        
        exit(0);
    }
    
    return userNum;
}

int pc(int pcNum)
{
    srand(time(0));
    pcNum = (rand() % 3 + 1);
    
    if (pcNum == 1)
    {
        pcChoice = "rock";
    }
    else if (pcNum == 2)
    {
        pcChoice = "paper";
    }
    else if (pcNum == 3)
    {
        pcChoice = "scissors";
    }
    
    return pcNum;
}

void result(int pcNum, int userNum)
{
    if (pcNum == 1)
    {
        if (userNum == 1)
        {
            cout << "Tie. Play again.";
        }
        else if (userNum == 2)
        {
            cout << "You win. Paper covers rock.";
        }
        else if (userNum == 3)
        {
            cout << "You lose. Rock breaks scissors.";
        }
    }
    else if (pcNum == 2)
    {
        if (userNum == 1)
        {
            cout << "You lose. Paper covers rock.";
        }
        else if (userNum == 2)
        {
            cout << "Tie. Play again.";
        }
        else if (userNum == 3)
        {
            cout << "You win. Scissors cut paper.";
        }
    }
    else if (pcNum == 3)
    {
        if (userNum == 1)
        {
            cout << "You win. Rock breaks scissors.";
        }
        else if (userNum == 2)
        {
            cout << "You lose. Scissors cut paper";
        }
        else if (userNum == 3)
        {
            cout << "Tie. Play again.";
        }
    }
}

Answer 1

void result();

这是一个函数声明，而不是函数调用。

您不能在函数中声明任何函数。此外，您已经声明了该功能。所以，我认为你想要的是：

result(userNum, pcNum);

Answer 2

请阅读标记为// CHANGE HERE的cmets

#include <iostream>
#include <ctime>
#include <cstdlib>
using namespace std;

// CHANGE HERE:
// 1. Changed function signatures
// 2. Removed unnecessary global variables
// 3. Removed unnecessary functions

int user();
int pc();
void result(int, int);

string userChoice, pcChoice;

int main()
{
    // CHANGE HERE: added local variables to store return values
    int userNum = user();
    int pcNum = pc();
    
    // CHANGE HERE: added endl
    cout << "You chose " << userChoice << endl << "They chose " << pcChoice << endl;
    
    // CHANGE HERE: call result function here
    result(pcNum, userNum);
    return 0;
}

int user()
{
    cout << "Choose rock, paper, or scissors: ";
    cin >> userChoice;
    
    if(userChoice == "rock")
    {
        return 1;
    }
    else if(userChoice == "paper")
    {
        return 2;
    }
    else if(userChoice == "scissors")
    {
        return 3;
    }
    
    cout << "Input invalid. Run again and enter rock, paper, or scissors." << endl;
    exit(0);
}

int pc()
{
    srand(time(0));
    // CHANGE HERE: make pcNum local variable
    int pcNum = (rand() % 3 + 1);
    
    if (pcNum == 1)
    {
        pcChoice = "rock";
    }
    else if (pcNum == 2)
    {
        pcChoice = "paper";
    }
    else if (pcNum == 3)
    {
        pcChoice = "scissors";
    }
    
    return pcNum;
}

void result(int pcNum, int userNum)
{
    if (pcNum == 1)
    {
        if (userNum == 1)
        {
            cout << "Tie. Play again.";
        }
        else if (userNum == 2)
        {
            cout << "You win. Paper covers rock.";
        }
        else if (userNum == 3)
        {
            cout << "You lose. Rock breaks scissors.";
        }
    }
    else if (pcNum == 2)
    {
        if (userNum == 1)
        {
            cout << "You lose. Paper covers rock.";
        }
        else if (userNum == 2)
        {
            cout << "Tie. Play again.";
        }
        else if (userNum == 3)
        {
            cout << "You win. Scissors cut paper.";
        }
    }
    else if (pcNum == 3)
    {
        if (userNum == 1)
        {
            cout << "You win. Rock breaks scissors.";
        }
        else if (userNum == 2)
        {
            cout << "You lose. Scissors cut paper";
        }
        else if (userNum == 3)
        {
            cout << "Tie. Play again.";
        }
    }
}