用二分查找法实现array_search

function array_search($a,$v){$b = 0;$n = count($a) -1;while($b <= $n){$s = floor(($b + $n)/2);if($v == $a[$s]) return $s;if($v > $a[$s]){$b = $s + 1;continue;}else{$n = $s - 1;continue;}return -1;}}