<?php
/**
 * TournamentMatrix - A dominance-directed graph implemented as a matrix.
 * See http://aix1.uottawa.ca/~jkhoury/graph.htm.
 */
class TournamentMatrix {
    private $tournamentArray;

    public function getArray() { return $this->tournamentArray; }
    public function setArray($array) { $this->tournamentArray = $array; }

    // Compute the power matrix (A=M+M^2):
    public function computePowers() {
        $array = $this->getArray();
        $result = $this->multiply($array, $array);
        $result = $this->add($array, $result);
        $result = $this->sumRows($result);
        return $result;
    }

    // Multiply two matrix arrays:
    private function multiply($array1, $array2) {
        for ($i=0; $i<count($array1); $i++)
            for ($j=0; $j<count($array1[0]); $j++) {
                $result[$i][$j] = 0;
                for ($k=0; $k<count($array1); $k++)
                    $result[$i][$j] += $array1[$i][$k] * $array2[$k][$j];
            }
        return $result;
    }

    // Add two matrix arrays:
    private function add($array1, $array2) {
        for ($i=0; $i<count($array1); $i++)
            for ($j=0; $j<count($array1[0]); $j++)
                $result[$i][$j] = $array1[$i][$j] + $array2[$i][$j];
        return $result;
    }

    // Sum (horizontally) the rows of a matrix array:
    private function sumRows($array) {
        for ($i=0; $i<count($array); $i++)
            for ($j=0; $j<count($array[0]); $j++)
                $result[$i] += $array[$i][$j];
        return $result;
    }
}
?>