
- strpos()查找字符串位置,如果查找字符在起始位置,返回0。
- substr($str, $start, $length)提取字符串
- substr_replace($old_string, $new_substring, $start, $length)替换子串
- 逐字节处理字符串
Look And Say序列:function lookAndSay($s){ // 将返回值初始化一个空串 $r = ''; $m = $s[0]; $n = 1; for ($i = 1; $j = strlen($s), $i < $j; $i++){ if ($s[$i] == $m){ $n++; }else{ $r .= $n.$m; $m = $s[$i]; $n = 1; } } return $r.$n.$m;}for ($i = 0, $s = 1; $i < 10; $i++){ $s = lookAndSay($s); print "$s\n";}// 1 11 21 1211 111221 312211 13112221 1113213211 31131211131221 13211311123113112211
- 字符或单词反转
人吐槽 | 人点赞 |
发表评论