52 lines
1.3 KiB
PHP
52 lines
1.3 KiB
PHP
|
<?php
|
||
|
|
|
||
|
|
$input = file_get_contents('./input.txt');
|
||
|
|
|
||
|
|
preg_match('/^target area: x=(\d+)\.\.(\d+), y=(-?\d+)\.\.(-?\d+)$/', $input, $matches);
|
||
|
|
|
||
|
|
[, $x_min, $x_max, $y_min, $y_max] = $matches;
|
||
|
|
$target = ['x_min' => $x_min, 'x_max' => $x_max, 'y_min' => $y_min, 'y_max' => $y_max];
|
||
|
|
|
||
|
|
function increment(&$x, &$y, &$x_velocity, &$y_velocity)
|
||
|
|
{
|
||
|
|
$x += $x_velocity;
|
||
|
|
$y += $y_velocity;
|
||
|
|
if ($x_velocity > 0) $x_velocity -= 1;
|
||
|
|
elseif ($x_velocity < 0) $x_velocity += 1;
|
||
|
|
else $x_velocity = 0;
|
||
|
|
$y_velocity -= 1;
|
||
|
|
}
|
||
|
|
|
||
|
|
function check($x, $y, $target)
|
||
|
|
{
|
||
|
|
return $x >= $target['x_min'] &&
|
||
|
|
$x <= $target['x_max'] &&
|
||
|
|
$y >= $target['y_min'] &&
|
||
|
|
$y <= $target['y_max'];
|
||
|
|
}
|
||
|
|
|
||
|
|
$max = 0;
|
||
|
|
for ($i = 1; $i < abs($target['x_min']); $i++) {
|
||
|
|
$tmp_max = 0;
|
||
|
|
for ($j = 1; $j < abs($target['y_min']); $j++) {
|
||
|
|
$x = 0;
|
||
|
|
$y = 0;
|
||
|
|
$x_velocity = $i;
|
||
|
|
$y_velocity = $j;
|
||
|
|
$tmp_max = max($tmp_max, $y);
|
||
|
|
while(!check($x, $y, $target)) {
|
||
|
|
echo sprintf('x: %s, y: %s%s', $x, $y, "\n");
|
||
|
|
increment($x, $y, $x_velocity, $y_velocity);
|
||
|
|
$tmp_max = max($tmp_max, $y);
|
||
|
|
if ($y <= $target['y_min']) {
|
||
|
|
break;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
if (check($x, $y, $target)) {
|
||
|
|
$max = max($max, $tmp_max);
|
||
|
|
}
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
echo $max;
|