Question

How to count the number of sorted rows in either increasing or decreasing order in a matrix using PHP

Answer 1

function sortedCount($matrix) {
    $result = 0;

    // Get the number of rows (first dimension)
    $rows = count($matrix);

    // Get the number of columns (second dimension)
    $cols = count($matrix[0]);

    // Check for strictly increasing rows
    for ($i = 0; $i < $rows; $i++) {
        for ($j = 0; $j < $cols - 1; $j++) {
            if ($matrix[$i][$j + 1] <= $matrix[$i][$j]) {
                break;
            }
        }
        if ($j == $cols - 1) {
            $result++;
        }
    }

    // Check for strictly decreasing rows
    for ($i = 0; $i < $rows; $i++) {
        for ($j = $cols - 1; $j > 0; $j--) {
            if ($matrix[$i][$j - 1] <= $matrix[$i][$j]) {
                break;
            }
        }
        if ($cols > 1 && $j == 0) {
            $result++;
        }
    }

    return $result;
}

$matrix = [
    [1, 2, 3, 4, 5],
    [2, 3, 1, 8, 7],
    [8, 7, 6, 5, 4],
    [5, 7, 8, 9, 10]
];

echo "Number of sorted rows: " . sortedCount($matrix) . "\n";


/*
run:

Number of sorted rows: 3

*/

 

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