erikccoder / cs50-php Goto Github PK

function vote($voter, $rank, $name)
{    
    global $candidates, $preferences;
    $num_candidates = count($candidates);    
    for($i=0; $i<$num_candidates; $i++)
    {
        if($candidates[$i]['name'] === $name)
        {
            $preferences[$voter][$rank] = $i;
        }        
    }
}

function print_winner()
{
    global $candidates, $preferences;
    $num_voters = count($preferences);
    $votes_to_win = ceil($num_voters*.5);
    foreach($candidates as $candidate)
    {
        if($candidate['vote'] > $votes_to_win)
        {
            printf($candidate['name'] . "\n");
            return 1;
        }
    }
    return 0;
}

function find_min()
{
    global $candidates, $preferences;
    $min_vote = 999999;
    foreach( $candidates as $candidate)
    {
        if(!$candidate['eliminated']){
            $vote = $candidate['vote'];
            if($min_vote > $vote)
            {
                $min_vote = $vote;   
            }            
        }
    }
    return $min_vote;
}

function eliminate($min)
{
    global $candidates;
    $num_candidates = count($candidates);    
    for($i=0; $i<$num_candidates; $i++)
    {
        if(!$candidates[$i]['eliminated'])
        {
            if($candidates[$i]['vote'] <= $min){
                $candidates[$i]['eliminated'] = 1;
            }
        }
    }
}

$candidates = [];
for($i=1; $i<$argc; $i++)
{
    $candidates[] = [
        'name' => $argv[$i],
        'vote' => 0,
        'eliminated' => 0,
    ];
}

$preferences = [];

$num_voters = -1;

do{
    $num_voters = get_int("Number of voters: ");
    // print_r([
    //     '$num_voters' => $num_voters,
    // ]);
}
while($num_voters <= 0);

$preferences = [];
for($j=0; $j<$num_voters; $j++)
{
    $pref = [];
    for($i=1; $i<$argc; $i++)
    {
        $pref[] = -1;
    }
    $preferences[] = $pref;
}


$num_input = $num_voters * ($argc-1);
$current_input = 0;


while($num_input >= $current_input + 1)
{
    $i = ($current_input % ($argc-1)) + 1;
    
    $name = get_string("Rank $i: ");
    vote(floor(($current_input)/3), floor($i-1), $name);
    $current_input++;
}

$stage = 0;
while($stage < $argc - 1 )
{    
    tabulate();
    $has_winner = print_winner();
    if(!$has_winner)
    {
        $min = find_min();
        $is_tie = is_tie($min);
        if($is_tie)
        {
            $stage = 999;                        
        }
        eliminate($min);
    }
    $stage += $has_winner ? 999 : 1;     
}

function setPreference($pref, $stage)
{
    global $candidates;
    $c_index = $pref[$stage];
    if(isset($c_index))
    {
        $candidate = $candidates[$c_index];
        if(isset($candidate))
        {
            if($candidate['eliminated'])
            {
                setPreference($pref, $stage+1);
            }
            else
            {
                $candidates[$c_index]['vote'] += 1;
            }
        }
    }
}

function tabulate()
{
    global $candidates, $preferences;
    $num_candidates = count($candidates);    
    for($i=0; $i<$num_candidates; $i++)
    {
        $candidates[$i]['vote'] = 0;
    }

    foreach($preferences as $pref)
    {   
        setPreference($pref, 0);
    }
}

function is_tie($min)
{
    global $candidates;
    $votes_to_check = -1;
    foreach( $candidates as $candidate)
    {
        if(!$candidate['eliminated'])
        {
            $vote = $candidate['vote'];            
            if($votes_to_check === -1)
            {
                $votes_to_check = $vote;
            }
            else if($votes_to_check != $vote)
            {
                return false;
            } 
        }
    }
    if($votes_to_check == -1){
        print_r([
            'error' => "votes_to_check: $votes_to_check which all candidates are eliminated"
        ]);
    }
    return true;
}