Puzzle01.php

<?php declare(strict_types=1);

namespace AdventOfCode2020;

echo sprintf('Puzzle 1 part 1: %d'.PHP_EOL, (new Puzzle01())->part1());
echo sprintf('Puzzle 1 part 2: %d'.PHP_EOL, (new Puzzle01())->part2());

final class Puzzle01
{
    public function part1(): int
    {
        foreach ($this->getInput() as $number1) {
            foreach ($this->getInput() as $number2) {
                if ($number1 + $number2 === 2020) {
                    return $number1 * $number2;
                }
            }
        }

        return 0;
    }

    public function part2(): int
    {
        foreach ($this->getInput() as $number1) {
            foreach ($this->getInput() as $number2) {
                foreach ($this->getInput() as $number3) {
                    if ($number1 + $number2 + $number3 === 2020) {
                        return $number1 * $number2 * $number3;
                    }
                }
            }
        }

        return 0;
    }

    private function getInput(): array
    {
        return [
            2004, 1823, 1628, 1867, 1073, 1951, 1909, 1761, 1093, 1992, 1986, 1106, 1537, 1905, 1233, 1961, 1760, 1562, 1781,
            1329, 1272, 1660, 1367, 1248, 1697, 1515, 1470, 1980, 1884, 1784, 1966, 1778, 1426, 1255, 1089, 1748, 1253, 1870,
            1651, 1131, 1623, 1595, 1128, 1014, 1863, 1855, 1203, 1395, 1521, 1365, 1202, 780, 1560, 1834, 1494, 1551, 1398,
            1190, 1975, 1940, 1217, 1793, 1310, 1070, 1865, 1307, 1735, 1897, 1410, 1994, 1541, 1569, 1731, 1238, 1193, 1226,
            1435, 1159, 1642, 1652, 1908, 1920, 1930, 1068, 1914, 1186, 1795, 1888, 1634, 1750, 1950, 1493, 1353, 1461, 1658,
            1856, 1301, 1538, 1948, 1998, 1847, 1880, 1657, 1536, 1457, 1762, 1706, 1894, 542, 1991, 1108, 1072, 1064, 1511,
            1496, 1480, 1955, 1604, 1766, 1983, 1713, 1234, 1503, 1583, 1729, 1140, 1006, 1600, 1699, 1280, 1891, 1996, 1375,
            1167, 1625, 1129, 1770, 1497, 1620, 1267, 1421, 1399, 1563, 1636, 1293, 1506, 1613, 1958, 1967, 1182, 1050, 1947,
            1787, 1774, 1928, 1896, 1303, 1826, 1132, 1254, 1752, 1510, 1705, 1229, 1558, 1989, 1567, 698, 1738, 1357, 1587,
            1316, 1838, 1311, 1057, 1644, 1135, 1300, 1134, 1577, 1381, 1806, 1176, 1993, 1769, 1633, 1450, 1819, 1973, 1694,
            969, 1987, 1095, 1717, 1933, 1593, 1045, 1355, 1459, 1619,
        ];
    }
}