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1
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<?php |
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2
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3
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declare(strict_types=1); |
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5
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namespace leetcode; |
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6
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7
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class AvailableCapturesForRook |
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{ |
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9
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public static function numRookCaptures(array $board): int |
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10
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{ |
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11
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[$m, $n] = [count($board), empty($board[0]) ? 0 : count($board[0])]; |
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if ($m === 0 || $n === 0) { |
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return 0; |
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} |
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15
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for ($i = 0; $i < $m; $i++) { |
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for ($j = 0; $j < $n; $j++) { |
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if ($board[$i][$j] === 'R') { |
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return self::helper($board, $i, $j, 0, 1) |
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+ self::helper($board, $i, $j, 0, -1) |
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+ self::helper($board, $i, $j, 1, 0) |
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+ self::helper($board, $i, $j, -1, 0); |
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} |
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} |
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} |
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return 0; |
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} |
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private static function helper(array $board, int $x, int $y, int $dx, int $dy): int |
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{ |
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[$m, $n] = [count($board), empty($board[0]) ? 0 : count($board[0])]; |
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32
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while ($x >= 0 && $x < $m && $y >= 0 && $y < $n && $board[$x][$y] !== 'B') { |
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33
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if ($board[$x][$y] === 'p') { |
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return 1; |
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35
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} |
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36
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[$x, $y] = [$x + $dx, $y + $dy]; |
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37
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} |
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39
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return 0; |
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40
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} |
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} |
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42
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