C++ 实现 2048 小游戏实战教程

3. 处理用户输入

我们需要监听键盘事件。这里演示基础的字符捕获，根据 W/A/S/D 映射到上下左右操作。

void processUserInput() {
    char userInput = getchar();
    switch (userInput) {
        case 'w': moveUp(gameBoard); break;
        case 's': moveDown(gameBoard); break;
        case 'a': moveLeft(gameBoard); break;
        case 'd': moveRight(gameBoard); break;
        default: break;
    }
}

4. 移动与合并逻辑

这是整个游戏的核心算法。以向上移动为例：每一列独立处理，非零元素向顶部靠拢，遇到相同数值则合并并停止该格子的进一步移动。

bool moveUp(int board[SIZE][SIZE]) {
    bool moved = false;
    for (int j = 0; j < SIZE; j++) {
        for (int i = 1; i < SIZE; i++) {
            if (board[i][j] != 0) {
                int k = i;
                // 向左上方寻找空位
                while (k > 0 && board[k-1][j] == 0) {
                    board[k-1][j] = board[k][j];
                    board[k][j] = 0;
                    k--;
                    moved = true;
                }
                // 检查是否可合并
                if (k > 0 && board[k-1][j] == board[k][j]) {
                    board[k-1][j] *= 2;
                    board[k][j] = 0;
                    moved = true;
                }
            }
        }
    }
    return moved;
}

// 向下、左、右的逻辑类似，只是遍历方向和比较索引不同
bool moveDown(int board[SIZE][SIZE]) {
    bool moved = false;
    for (int j = 0; j < SIZE; j++) {
        for (int i = SIZE - 2; i >= 0; i--) {
            if (board[i][j] != 0) {
                int k = i;
                while (k < SIZE - 1 && board[k+1][j] == 0) {
                    board[k+1][j] = board[k][j];
                    board[k][j] = 0;
                    k++;
                    moved = true;
                }
                if (k < SIZE - 1 && board[k+1][j] == board[k][j]) {
                    board[k+1][j] *= 2;
                    board[k][j] = 0;
                    moved = true;
                }
            }
        }
    }
    return moved;
}

bool moveLeft(int board[SIZE][SIZE]) {
    bool moved = false;
    for (int i = 0; i < SIZE; i++) {
        for (int j = 1; j < SIZE; j++) {
            if (board[i][j] != 0) {
                int k = j;
                while (k > 0 && board[i][k-1] == 0) {
                    board[i][k-1] = board[i][k];
                    board[i][k] = 0;
                    k--;
                    moved = true;
                }
                if (k > 0 && board[i][k-1] == board[i][k]) {
                    board[i][k-1] *= 2;
                    board[i][k] = 0;
                    moved = true;
                }
            }
        }
    }
    return moved;
}

bool moveRight(int board[SIZE][SIZE]) {
    bool moved = false;
    for (int i = 0; i < SIZE; i++) {
        for (int j = SIZE - 2; j >= 0; j--) {
            if (board[i][j] != 0) {
                int k = j;
                while (k < SIZE - 1 && board[i][k+1] == 0) {
                    board[i][k+1] = board[i][k];
                    board[i][k] = 0;
                    k++;
                    moved = true;
                }
                if (k < SIZE - 1 && board[i][k+1] == board[i][k]) {
                    board[i][k+1] *= 2;
                    board[i][k] = 0;
                    moved = true;
                }
            }
        }
    }
    return moved;
}

5. 判断游戏结束

需要同时满足两个条件：一是检测到 2048 即获胜；二是棋盘已满且无相邻相同数字，即无法移动。

bool isGameWon() {
    for (int i = 0; i < SIZE; i++) {
        for (int j = 0; j < SIZE; j++) {
            if (gameBoard[i][j] == 2048) return true;
        }
    }
    return false;
}

bool isGameOver() {
    bool canMove = false;
    for (int i = 0; i < SIZE; i++) {
        for (int j = 0; j < SIZE; j++) {
            // 有空位
            if (gameBoard[i][j] == 0) {
                canMove = true;
                break;
            }
            // 横向或纵向有可合并项
            if (i < SIZE - 1 && gameBoard[i][j] == gameBoard[i + 1][j]) {
                canMove = true;
                break;
            }
            if (j < SIZE - 1 && gameBoard[i][j] == gameBoard[i][j + 1]) {
                canMove = true;
                break;
            }
        }
        if (canMove) break;
    }
    return !canMove;
}

通过以上模块的组合，我们就构建了一个完整的 2048 游戏内核。实际项目中，你可以在此基础上添加 UI 渲染、音效或计分系统。