$pileTops = array();
// sort into piles
foreach ($n as $x) {
// binary search
$low = 0;
$high = count($pileTops) - 1;
while ($low <= $high) {
$mid = (int) (($low + $high) / 2);
if ($pileTops[$mid]->val >= $x) {
$high = $mid - 1;
} else {
$low = $mid + 1;
}
}
$i = $low;
$node = new Node();
$node->val = $x;
if ($i != 0) {
$node->back = $pileTops[$i - 1];
}
$pileTops[$i] = $node;
}
$result = array();
for ($node = count($pileTops) ? $pileTops[count($pileTops) - 1] : NULL; $node != NULL; $node = $node->back) {
$result[] = $node->val;
}
return array_reverse($result);
}
print_r(lis(array(3, 2, 6, 4, 5, 1)));
print_r(lis(array(0, 8, 4, 12, 2, 10, 6, 14, 1, 9, 5, 13, 3, 11, 7, 15)));
$P = [0];
$L = 0;
for ($i = 0; $i < $N; $i++) {
$j = 0;
for ($pos = $L; $pos >= 1; $pos--) {
if ($X[$M[$pos]] < $X[$i]) {
$j = $pos;
break;
}
}
$P[$i] = $M[$j];
if ($j === $L || $X[$i] < $X[$M[$j + 1]]) {
$M[$j + 1] = $i;
$L = max($L, $j + 1);
}
}
$result = [];
$pos = $M[$L];
for ($i = $L - 1; $i >= 0; $i--) {
$result[$i] = $X[$pos];
$pos = $P[$pos];
}
return $result;
}
// Test cases
var_dump(lis([0, 8, 4, 12, 2, 10, 6, 14, 1, 9, 5, 13, 3, 11, 7, 15]));
// array -> 0, 2, 6, 9, 11, 15
var_dump(lis([0, 1, 2, 3, 4, 5, 1, 3, 8]));
// array -> 0, 1, 2, 3, 4, 5, 8
var_dump(lis([0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 2, 3, 0, 0, 0, 1, 1, 0, 1, 1, 0, 1, 0, 3]));
// array -> 0, 1, 2, 3
