Question

目前我正在尝试创建一个程序，它将从头开始自动生成一个完整的数独板，尽管相同的功能可以通过微小的改动来解决部分填充的数独板。问题是，当你在板上加载一个新的数字时，你显然必须检查这个数字是否已经存在于同一列或行中，而且也是在加载它的3x3方块中。对程序的一部分使用嵌套的switch语句，你必须根据相同的3x3方格中的数字检查数字，尽管break语句都显示在正确的位置。 compliler说的是第二个case语句的第一个数字，它是嵌套switch语句的一部分：＆＃34;错误：case标签值已经出现在这个switch＆＃34;即使这个数字还没有，问题是为什么？

以下是代码：

bool SudokuClass::checkPresentGrid(int &temporary, int row, int column)
{
bool indicator;
 switch (row)
{
case 0 || 3 || 6:       //If the number is being loaded into row 0,3 or 6
    switch (column)
    {
    case 0 || 3 || 6:   //Check all other spaces in the same 3x3 grid   
        if (temporary == (completeSudoku[row + 1][column + 1] || completeSudoku[row + 1][column + 2] || completeSudoku[row + 2][column + 1] || completeSudoku[row + 2][column + 2]))
        {
            indicator = true;
        }
        break;
    case 1 || 4 || 7:
        if (temporary == (completeSudoku[row + 1][column - 1] || completeSudoku[row + 1][column + 1] || completeSudoku[row + 2][column - 1] || completeSudoku[row + 2][column + 1]))
        {
            indicator = true;
        }
        break;
    case 2 || 5 || 8:
        if (temporary == (completeSudoku[row + 1][column - 2] || completeSudoku[row + 1][column - 1] || completeSudoku[row + 2][column - 2] || completeSudoku[row + 2][column - 1]))
        {
            indicator = true;
        }
        break;
    }
    break;
case 1 || 4 || 7:               //If the number is being loaded into row 1, 4 or 7
    switch (column)
    {
    case 0 || 3 || 6:   //Check all other spaces in the same 3x3 grid   
        if (temporary == (completeSudoku[row - 1][column + 1] || completeSudoku[row - 1][column + 2] || completeSudoku[row + 1][column + 1] || completeSudoku[row + 1][column + 2]))
        {
            indicator = true;
        }
        break;
    case 1 || 4 || 7:
        if (temporary == (completeSudoku[row - 1][column - 1] || completeSudoku[row - 1][column + 1] || completeSudoku[row + 1][column - 1] || completeSudoku[row + 1][column + 1]))
        {
            indicator = true;
        }
        break;
    case 2 || 5 || 8:
        if (temporary == (completeSudoku[row - 1][column - 2] || completeSudoku[row - 1][column - 1] || completeSudoku[row + 1][column - 2] || completeSudoku[row + 1][column - 1]))
        {
            indicator = true;
        }
        break;
    }
    break;
case 2 || 5 || 8:               //If the number is being loaded into row 2, 5 or 8
    switch (column)
    {
    case 0 || 3 || 6:           //Check all other spaces in the same 3x3 grid   
        if (temporary == (completeSudoku[row - 2][column + 1] || completeSudoku[row - 2][column + 2] || completeSudoku[row - 1][column + 1] || completeSudoku[row - 1][column + 2]))
        {
            indicator = true;
        }
        break;
    case 1 || 4 || 7:
        if (temporary == (completeSudoku[row - 2][column - 1] || completeSudoku[row - 2][column + 1] || completeSudoku[row - 1][column - 1] || completeSudoku[row - 1][column + 1]))
        {
            indicator = true;
        }
        break;
    case 2 || 5 || 8:
        if (temporary == (completeSudoku[row - 2][column - 2] || completeSudoku[row - 2][column - 1] || completeSudoku[row - 1][column - 2] || completeSudoku[row - 1][column - 1]))
        {
            indicator = true;
        }
        break;
    }
    break;
}
return indicator;

}

Answer 1

更改

case 0 || 3 || 6:       //If the number is being loaded into row 0,3 or 6

到

case 0:
case 3:
case 6:       //If the number is being loaded into row 0,3 or 6

...依此类推，与您的其他case语句一起使用。

您的代码case 0 || 3 || 6

评估为case (0 || 3 || 6)

变为case (false || true || true)

变成case (true)，这不是你想要的。

Answer 2

case语句必须是值。您正在尝试与EXPRESSIONS的结果进行比较。

e.g。鉴于此代码：

switch($foo) {
   case $bar || $baz: 
       ...
}

重写为传统的if（），它将执行完全相同的：

$temp = $bar || $baz;   // boolean OR operation, $temp becomes true/false
if ($foo == $temp) {
    ...

您正试图将其视为：

if (($temp == $bar) || ($temp == $baz))

它肯定不是。

如果要比较多个值并让每个值执行相同的代码，请使用switch直通行为：

switch($foo) {
    case $bar:
    case $baz:
          .... do something
          break;

嵌套的Switch语句

2 个答案: