井字游戏不起作用

Question

因此，大约一周前我学习了编程。 我决定制作一个井字游戏作为一项业余爱好项目，我启动并运行了基本的游戏输入法，但其中一个方面不起作用。 我编写了一段非常简单的代码，以验证有人打5步棋是否赢了。 一旦有人获胜，就应该显示“ Game Over！”。 但这不是出于某种原因。 有人可以帮忙吗？ _ __ _ __ _ __ _ ___ 注意：代码中验证人是否成功的方法还不完整。 它仅用于行，因为当我对其进行测试时，它不起作用。

#include <iostream>
#include <cstdlib>

using namespace std;
int main()
{
    char grid[3][3];
    int p;
    cout << "Enter column number. \n";
    cin >> p;
    int o;
    cout << "Enter row number. \n";
    cin >> o;
    for (int y = 0; y < 3; y++)
    {
        for (int x = 0; x < 3; x++)
        {
            grid[x][y] = '-';
            grid[o][p] = 'X';
            cout << grid[x][y] << " ";
        }
        cout << endl;
    }
    int q;
    cout << "Enter column number. \n";
    cin >> q;
    int r;
    cout << "Enter row number. \n";
    cin >> r;
    for (int y = 0; y < 3; y++)
    {
        for (int x = 0; x < 3; x++)
        {
            grid[x][y] = '-';
            grid[o][p] = 'X';
            grid[r][q] = 'O';
            cout << grid[x][y] << " ";
        }
        cout << endl;
    }
    int s;
    cout << "Enter column number. \n";
    cin >> s;
    int t;
    cout << "Enter row number. \n";
    cin >> t;
    for (int y = 0; y < 3; y++)
    {
        for (int x = 0; x < 3; x++)
        {
            grid[x][y] = '-';
            grid[o][p] = 'X';
            grid[r][q] = 'O';
            grid[t][s] = 'X';
            cout << grid[x][y] << " ";
        }
        cout << endl;
    }
    int v;
    cout << "Enter column number. \n";
    cin >> v;
    int b;
    cout << "Enter row number. \n";
    cin >> b;
    for (int y = 0; y < 3; y++)
    {
        for (int x = 0; x < 3; x++)
        {
            grid[x][y] = '-';
            grid[o][p] = 'X';
            grid[r][q] = 'O';
            grid[t][s] = 'X';
            grid[b][v] = 'O';
            cout << grid[x][y] << " ";
        }
        cout << endl;
    }
    int f;
    cout << "Enter column number. \n";
    cin >> f;
    int g;
    cout << "Enter row number. \n";
    cin >> g;
    for (int y = 0; y < 3; y++)
    {
        for (int x = 0; x < 3; x++)
        {
            grid[x][y] = '-';
            grid[o][p] = 'X';
            grid[r][q] = 'O';
            grid[t][s] = 'X';
            grid[b][v] = 'O';
            grid[g][f] = 'X';
            cout << grid[x][y] << " ";
        }
        cout << endl;
    }
    if (grid[0][0] == grid[0][1] == grid[0][2] || grid[1][0] == grid[1][1] == grid[1][2] || grid[2][0] == grid[2][1] == grid[2][2])
    {
        cout << "Game Over! \n\n";
    }
    int i;
    cout << "Enter column number. \n";
    cin >> i;
    int u;
    cout << "Enter row number. \n";
    cin >> u;
    for (int y = 0; y < 3; y++)
    {
        for (int x = 0; x < 3; x++)
        {
            grid[x][y] = '-';
            grid[o][p] = 'X';
            grid[r][q] = 'O';
            grid[t][s] = 'X';
            grid[b][v] = 'O';
            grid[g][f] = 'X';
            grid[u][i] = 'O';
            cout << grid[x][y] << " ";
        }
        cout << endl;
    }
    if (grid[0][0] == grid[0][1] == grid[0][2] || grid[1][0] == grid[1][1] == grid[1][2] || grid[2][0] == grid[2][1] == grid[2][2])
    {
        cout << "Game Over! \n\n";
    }
    int a1;
    cout << "Enter column number. \n";
    cin >> a1;
    int e1;
    cout << "Enter row number. \n";
    cin >> e1;
    for (int y = 0; y < 3; y++)
    {
        for (int x = 0; x < 3; x++)
        {
            grid[x][y] = '-';
            grid[o][p] = 'X';
            grid[r][q] = 'O';
            grid[t][s] = 'X';
            grid[b][v] = 'O';
            grid[g][f] = 'X';
            grid[u][i] = 'O';
            grid[e1][a1] = 'X';
            cout << grid[x][y] << " ";
        }
        cout << endl;
    }
    if (grid[0][0] == grid[0][1] == grid[0][2] || grid[1][0] == grid[1][1] == grid[1][2] || grid[2][0] == grid[2][1] == grid[2][2])
    {
        cout << "Game Over! \n\n";
    }
    int a8;
    cout << "Enter column number. \n";
    cin >> a8;
    int b8;
    cout << "Enter row number. \n";
    cin >> b8;
    for (int y = 0; y < 3; y++)
    {
        for (int x = 0; x < 3; x++)
        {
            grid[x][y] = '-';
            grid[o][p] = 'X';
            grid[r][q] = 'O';
            grid[t][s] = 'X';
            grid[b][v] = 'O';
            grid[g][f] = 'X';
            grid[u][i] = 'O';
            grid[e1][a1] = 'X';
            grid[b8][a8] = 'O';
            cout << grid[x][y] << " ";
        }
        cout << endl;
    }
    if (grid[0][0] == grid[0][1] == grid[0][2] || grid[1][0] == grid[1][1] == grid[1][2] || grid[2][0] == grid[2][1] == grid[2][2])
    {
        cout << "Game Over! \n\n";
    }
    int a9;
    cout << "Enter column number. \n";
    cin >> a9;
    int b9;
    cout << "Enter row number. \n";
    cin >> b9;
    for (int y = 0; y < 3; y++)
    {
        for (int x = 0; x < 3; x++)
        {
            grid[x][y] = '-';
            grid[o][p] = 'X';
            grid[r][q] = 'O';
            grid[t][s] = 'X';
            grid[b][v] = 'O';
            grid[g][f] = 'X';
            grid[u][i] = 'O';
            grid[e1][a1] = 'X';
            grid[b8][a8] = 'O';
            grid[b9][a9] = 'X';
            cout << grid[x][y] << " ";
        }
        cout << endl;
    }
    if (grid[0][0] == grid[0][1] == grid[0][2] || grid[1][0] == grid[1][1] == grid[1][2] || grid[2][0] == grid[2][1] == grid[2][2])
    {
        cout << "Game Over! \n\n";
    }
}

Answer 1

在C ++中， ==符号不能像代数类那样工作。 在C ++中，表达式a == b == c具有非常不同的含义。 在C ++中，它仅适用于成对的项，并返回true或false值。 （请参阅下文。）

要查看3个事物是否彼此相等，您需要说(a == b && b == c) 。 您的网格检查将需要如下所示：

if ( (grid[0][0] == grid[0][1] && grid[0][1] == grid[0][2]) || 
     (grid[1][0] == grid[1][1] && grid[1][1] == grid[1][2]) ||
     (grid[2][0] == grid[2][1] && grid[2][1] == grid[2][2]) )

您还会注意到我在其中加了多余的括号。 它们不是严格必需的，但是某些编译器会在混合&&和||时发出警告。 在相同的表达中。 括号使您可以将要分组的项目明确，并将平息这些警告。

---

那么，什么是 C ++编译器与您的代码在做什么？ 您已经编写了grid[0][0] == grid[0][1] == grid[0][2] 。 编译器根据其运算符优先级规则将其解释为(grid[0][0] == grid[0][1]) == grid[0][2] 。

编译器将首先比较grid[0][0]与grid[0][1] 。 根据它们是否相等，这将产生一个true或false布尔值（C ++ bool ）。 到现在为止还挺好。

比较之后，它将bool结果与grid[0][2] 。 由于grid[0][2]是一个char ，它将bool值提升为数值。 true变为1， false变为0。所有网格值都不具有值0或1-它们全都是'-' ， 'X'或'O' ，因此第二次比较总是失败。

对于所有三行重复相同的情况。

Answer 2

据我了解，您不能写：

grid[0][0] == grid[0][1] == grid[0][2]

你应该有：

grid[0][0] == grid[0][1] && grid[0][1]== grid[0][2]

在C ++中，它们是二进制运算符，因此==只能应用于两个变量，不能链接到三个变量。 现在，它将第一个结果（是/否）与第三个数字进行比较。

我的资料来源：

C ++井字游戏

Answer 3

如果您使用一个数组并将框1到9编号，则程序将小很多：

+---+---+---+
| 1 | 2 | 3 |
+---+---+---+
| 4 | 5 | 6 |
+---+---+---+
| 7 | 8 | 9 |
+---+---+---+

该数组将如下所示：

const unsigned int BOARD_CAPACITY = 9;
unsigned int board[BOARD_CAPACITY + 1];

board数组声明有一个额外的插槽，因此您可以安全地使用索引1到9。

单行检查：

bool row_wins = false;
if ((board[1] == board[2]) && (board[2] == board[3]))
{
  row_wins = true;
}