1

2 //--------------------3 // 基本数据结构算法4 //--------------------5 //二分查找(数组里查找某个元素)

6 function bin_sch($array, $low, $high, $k){7 if ( $low <= $high){8 $mid = intval(($low+$high)/2);9 if ($array[$mid] == $k){10 return $mid;11 }elseif ( $k < $array[$mid]){12 return bin_sch($array, $low, $mid-1, $k);13 }else{14 return bin_sch($array, $mid+ 1, $high, $k);15 }16 }17 return -1;18 }19 //顺序查找(数组里查找某个元素)

20 function seq_sch($array, $n, $k){21 $array[$n] = $k;22 for($i=0; $i

34 function delete_array_element($array , $i)35 {36 $len = count($array);37 for ($j= $i; $j

44 function bubble_sort( $array)45 {46 $count = count( $array);47 if ($count <= 0 ) return false;48 for($i=0 ; $i$i; $j--){50 if ($array[$j] < $array [$j-1]){51 $tmp = $array[$j];52 $array[$j] = $array[ $j-1];53 $array [$j-1] = $tmp;54 }55 }56 }57 return $array;58 }59 //快速排序(数组排序)

60 function quick_sort($array) {61 if (count($array) <= 1) return $array;62 $key = $array [0];63 $left_arr = array();64 $right_arr = array();65 for ($i= 1; $i

69 $right_arr[] = $array[$i];70 }71 $left_arr = quick_sort($left_arr);72 $right_arr = quick_sort( $right_arr);73 return array_merge($left_arr , array($key), $right_arr);74 }75

76 //------------------------77 // PHP内置字符串函数实现78 //------------------------79 //字符串长度

80 function strlen ($str)81 {82 if ($str == '' ) return 0;83 $count = 0;84 while (1){85 if ( $str[$count] != NULL){86 $count++;87 continue;88 }else{89 break;90 }91 }92 return $count;93 }94 //截取子串

95 function substr($str, $start, $length=NULL)96 {97 if ($str== '' || $start>strlen($str )) return;98 if (($length!=NULL) && ( $start>0) && ($length> strlen($str)-$start)) return;99 if (( $length!=NULL) && ($start< 0) && ($length>strlen($str )+$start)) return;100 if ($length == NULL) $length = (strlen($str ) - $start);101

102 if ($start < 0){103 for ($i=(strlen( $str)+$start); $i 0){108 for ($i= $start; $i

120 function strrev($str)121 {122 if ($str == '') return 0;123 for ($i=(strlen($str)- 1); $i>=0; $i --){124 $rev_str .= $str[$i];125 }126 return $rev_str;127 }128

129 //字符串比较

130 function strcmp($s1, $s2)131 {132 if (strlen($s1) < strlen($s2)) return -1;133 if (strlen($s1) > strlen( $s2)) return 1;134 for ($i =0; $i

144 //查找字符串

145 function strstr($str, $substr)146 {147 $m = strlen($str);148 $n = strlen($substr);149 if ($m < $n) return false;150 for ($i=0; $i <=($m-$n+1); $i ++){151 $sub = substr( $str, $i, $n);152 if ( strcmp($sub, $substr) == 0) return $i;153 }154 return false;155 }156 //字符串替换

157 function str_replace($substr , $newsubstr, $str)158 {159 $m = strlen($str);160 $n = strlen($substr);161 $x = strlen($newsubstr);162 if (strchr($str, $substr ) == false) return false;163 for ( $i=0; $i<=($m- $n+1); $i++){164 $i = strchr($str, $substr);165 $str = str_delete ($str, $i, $n);166 $str = str_insert($str, $i, $newstr);167 }168 return $str;169 }170

171 //--------------------172 // 自实现字符串处理函数173 //--------------------174 //插入一段字符串

175 function str_insert($str, $i , $substr)176 {177 for($j=0 ; $j

187 function str_delete($str , $i, $j)188 {189 for ( $c=0; $c

199 function strcpy($s1, $s2)200 {201 if (strlen($s1)==NULL || !isset( $s2)) return;202 for ($i=0 ; $i

208 function strcat($s1 , $s2)209 {210 if (!isset($s1) || !isset( $s2)) return;211 $newstr = $s1;212 for($i=0; $i

218 function php_encode($str)219 {220 if ( $str=='' && strlen( $str)>128) return false;221 for( $i=0; $i31 && $c <107) $c += 20;224 if ($c>106 && $c <127) $c -= 75;225 $word = chr($c);226 $s .= $word;227 }228 return $s;229 }230 //简单解码函数(与php_encode函数对应)

231 function php_decode($str)232 {233 if ( $str=='' && strlen($str )>128) return false;234 for( $i=0; $i106 && $c<127 ) $c = $c-20;237 if ($c>31 && $c< 107) $c = $c+75;238 $word = chr( $c);239 $s .= $word;240 }241 return $s;242 }243 //简单加密函数(与php_decrypt函数对应)

244 function php_encrypt($str)245 {246 $encrypt_key = 'abcdefghijklmnopqrstuvwxyz1234567890';247 $decrypt_key = 'ngzqtcobmuhelkpdawxfyivrsj2468021359';248 if ( strlen($str) == 0) return false;249 for ($i=0; $i

260 function php_decrypt($str)261 {262 $encrypt_key = 'abcdefghijklmnopqrstuvwxyz1234567890';263 $decrypt_key = 'ngzqtcobmuhelkpdawxfyivrsj2468021359';264 if ( strlen($str) == 0) return false;265 for ($i=0; $i

276 ?>