<?php//冒泡$str = "31 42 12 4 49 8 7 6 5 66 90";function maoPao($str){ $arr = explode(" ", $str); $total = count($arr); for($i=0; $i<$total; $i++){ for($j=$i+1; $j<$total; $j++){ if($arr[$i]>$arr[$j]){ $tmp = $arr[$i]; $arr[$i] = $arr[$j]; $arr[$j] = $tmp; } } } return $arr;}var_dump(maoPao($str));<?php#根据字符串组合可能$str = "abcdefg";function getStrType($str,$total){ $strlen = strlen($str); if($strlen > 0){ for($i=0;$i<$strlen;$i++){ $newStr .= $str[$i]; //var_dump($newStr); $total[] = $newStr; } return getStrType(substr($str,1),$total); } return $total;}$total = getStrType($str, []);echo count($total);
