<?php

$register = array(0,0,0,0);

function execute_code($opnr, $a, $b, $c)
{
    global $register;

    switch ($opnr)
    {
        case 12: //ADDR //FOUND
            $register[$c] = $register[$a] + $register[$b];
            break;
        case 14: //ADDI //FOUND
            $register[$c] = $register[$a] + $b;
            break;
        case 7: //mulr //FOUND
            $register[$c] = $register[$a] * $register[$b];
            break;
        case 3: //muli //FOUND
            $register[$c] = $register[$a] * $b;
            break;
        case 10: //banr
            $register[$c] = $register[$a] & $register[$b];
            break;
        case 15: //bani
            $register[$c] = $register[$a] & $b;
            break;
        case 5: //borr //FOUND
            $register[$c] = $register[$a] | $register[$b];
            break;
        case 6: //bori  //FOUND
            $register[$c] = $register[$a] | $b;
            break;
        case 0: //setr
            $register[$c] = $register[$a];
            break;
        case 9: //seti //FOUND
            $register[$c] = $a;
            break;
        case 13: //gtir
            $register[$c] = $a > $register[$b] ?1:0;
            break;
        case 2: //gtri
            $register[$c] = $register[$a] > $b ?1:0;
            break;
        case 8: //gtrr
            $register[$c] = $register[$a] > $register[$b] ?1:0;
            break;
        case 4: //eqir
            $register[$c] = $a === $register[$b] ?1:0;
            break;
        case 11: //eqri //FOUND
            $register[$c] = $register[$a] === $b ?1:0;
            break;
        case 1: //eqrr
            $register[$c] = $register[$a] === $register[$b] ?1:0;
            break;

    }
}

function check_code($code, $start, $end)
{
    global $register, $opcodes, $count;

    $ocount = 0;
    for($i=0;$i<=15;$i++)
    {
        $register = $start;
        execute_code($i,$code[1], $code[2], $code[3]);

        if($register[0] == $end[0] && $register[1] == $end[1] && $register[2] == $end[2] && $register[3] == $end[3])
        {
            $found = array(0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15);

            $opcodes[$i]++;
            if(!in_array($i,$found) && !in_array($code[0],$found)) {
                printf('Works for %d is %d', $i, $code[0]);
                echo PHP_EOL;
            }
            $ocount++;
        }
    }
    echo PHP_EOL;
    if($ocount > 2)
        $count++;
}
$input = file('input.txt');

$opcodes = array_fill(0,17,0);
$start_register = array();
$end_register = array();
$code = array();
$count = 0;

foreach ($input as $line)
{
    if(stripos($line,'Before: [') !== false)
    {
        //set register
        $start_register = array_map('intval', explode(', ', substr($line, 9, 10)));
    } else if(stripos($line,'After:  [') !== false)
    {
        //set register
        $end_register = array_map('intval', explode(', ', substr($line, 9, 10)));

        check_code($code, $start_register, $end_register);
    } else if(strlen($line) > 4)
    {
        $code = array_map('intval', explode(' ', $line));

    }


}

var_dump($opcodes);
var_dump($count);/**/

$input = file('program.txt');
foreach ($input as $line)
{
    $code = array_map('intval', explode(' ', $line));
    execute_code($code[0],$code[1],$code[2],$code[3]);
}

var_dump($register);