2020-10-29
php解决约瑟夫环算法实例分析

php解决约瑟夫环算法实例分析

本文实例讲述了php解决约瑟夫环算法。分享给大家供大家参考,具体如下: 今天偶遇一道算法题 “约瑟夫环”是一个数学的应用问题:一群猴子排成一圈,按1,2,…,n依次编号。然后从第1只开始数,数到第m只,把它踢出圈,从它后面再开始数, 再数到第m只,在把它踢出去…,如此不停的进行下去, 直到最后只剩下一只猴子为止,那只猴子就叫做大王。要求编程模拟此过程,输入m、n, 输出最后那个大王的编号。 方法一:递归算法 function killMonkey($monkeys , $m , $current = 0){ $number = count($monkeys); $num = 1; if(count($monkeys) == 1){ echo $monkeys[0]."成为猴王了"; return; } else{ while($num++ < $m){ $current++ ; $current = $current%$number; } echo $monkeys[$current]."的猴子被踢掉了<br/>"; array_splice($monkeys , $current , 1); killMonkey($monkeys , $m , $current); } } $monkeys = array(1 , 2 , 3 , 4 , 5 , 6 , 7, 8 , 9 , 10); //monkeys的编号 $m = 3; //数到第几只猴子被踢出 killMonkey($monkeys , $m); 运行结果: 3的猴子被踢掉了 6的猴子被踢掉了 9的猴子被踢掉了 2的猴子被踢掉了 7的猴子被踢掉了 1的猴子被踢掉了 8的猴子被踢掉了 5的猴子被踢掉了 10的猴子被踢掉了 4成为猴王了 方法二:线性表应用 最后这个算法最牛, 哦,是这样的,每个猴子出列后,剩下的猴子又组成了另一个子问题。只是他们的编号变化了。第一个出列的猴子肯定是a[1]=m(mod)n(m/n的余数),他除去后剩下的猴子是a[1]+1,a[1]+2,…,n,1,2,…a[1]-2,a[1]-1,对应的新编号是1,2,3…n-1。设此时某个猴子的新编号是i,他原来的编号就是(i+a[1])%n。于是,这便形成了一个递归问题。假如知道了这个子问题(n-1个猴子)的解是x,那么原问题(n个猴子)的解便是:(x+m%n)%n=(x+m)%n。问题的起始条件:如果n=1,那么结果就是1。 function yuesefu($n,$m) { $r=0; for($i=2; $i<=$n; $i++) { $r=($r+$m)%$i; } return $r+1; } echo yuesefu(10,3)."是猴王"; 运行结果: 4是猴王 更多关于PHP相关内容感兴趣的读者可查看本站专题:《PHP数据结构与算法教程》、《php程序设计算法总结》、《php字符串(string)用法总结》、《PHP数组(Array)操作技巧大全》、《PHP常用遍历算法与技巧总结》及《PHP数学运算技巧总结》 希望本文所述对大家PHP程序设计有所帮助。...
技术教程 680次浏览 0条评论
2020-10-28
php经典趣味算法实例代码

php经典趣味算法实例代码

1、一群猴子排成一圈,按1,2,…,n依次编号。然后从第1只开始数,数到第m只,把它踢出圈,从它后面再开始数,再数到第m只,在把它踢出去…,如此不停的进行下去,直到最后只剩下一只猴子为止,那只猴子就叫做大王。要求编程模拟此过程,输入m、n, 输出最后那个大王的编号。 function king($n, $m){ $monkeys = range(1, $n); //创建1到n数组 $i=0; while (count($monkeys)>1) { //循环条件为猴子数量大于1 if(($i+1)%$m==0) { //$i为数组下标;$i+1为猴子标号 unset($monkeys[$i]); //余数等于0表示正好第m个,删除,用unset删除保持下标关系 } else { array_push($monkeys,$monkeys[$i]); //如果余数不等于0,则把数组下标为$i的放最后,形成一个圆形结构 unset($monkeys[$i]); } $i++;//$i 循环+1,不断把猴子删除,或 push到数组 } return current($monkeys); //猴子数量等于1时输出猴子标号,得出猴王 } echo king(6,3); 2、有一母牛,到4岁可生育,每年一头,所生均是一样的母牛,到15岁绝育,不再能生,20岁死亡,问n年后有多少头牛。 function niu($y){ static $num= 1; //定义静态变量;初始化牛的数量为1 for ($i=1; $i <=$y ; $i++) { if($i>=4 && $i<15){ //每年递增来算,4岁开始+1,15岁不能生育 $num++; niu($y-$i); //递归方法计算小牛$num,小牛生长年数为$y-$i }else if($i==20){ $num--; //20岁死亡减一 } return $num; } } 3、杨辉三角 <?php /* 默认输出十行,用T(值)的形式可改变输出行数 */ class T{ private $num; public function __construct($var=10) { if ($var<3) die("值太小啦!"); $this->num=$var; } public function display(){ $n=$this->num; $arr=array(); //$arr=array_fill(0,$n+1,array_fill(0,$n+1,0)); $arr[1]=array_fill(0,3,0); $arr[1][1]=1; echo str_pad(" ",$n*12," "); printf("%3d",$arr[1][1]); echo "<br/>"; for($i=2;$i<=$n;$i++){ $arr[$i]=array_fill(0,($i+2),0); for($j=1;$j<=$i;$j++){ if($j==1) echo str_pad(" ",($n+1-$i)*12," "); printf("%3d",$arr[$i][$j]=$arr[$i-1][$j-1]+$arr[$i-1][$j]); echo " "; } echo"<br/>"; } } } $yh=new T('3'); //$yh=new T(数量); $yh->display(); ?> 4.冒泡排序 function maopao($arr){ $len = count($arr); for($k=0;$k<=$len;$k++) { for($j=$len-1;$j>$k;$j--){ if($arr[$j]<$arr[$j-1]){ $temp = $arr[$j]; $arr[$j] = $arr[$j-1]; $arr[$j-1] = $temp; } } } return $arr; } 5.快速排序 function quickSort($arr) { //先判断是否需要继续进行 $length = count($arr); if($length <= 1) { return $arr; } //选择第一个元素作为基准 $base_num = $arr[0]; //遍历除了标尺外的所有元素,按照大小关系放入两个数组内 //初始化两个数组 $left_array = array(); //小于基准的 $right_array = array(); //大于基准的 for($i=1; $i<$length; $i++) { if($base_num > $arr[$i]) { //放入左边数组 $left_array[] = $arr[$i]; } else { //放入右边 $right_array[] = $arr[$i]; } } //再分别对左边和右边的数组进行相同的排序处理方式递归调用这个函数 $left_array = quickSort($left_array); $right_array = quickSort($right_array); //合并 return array_merge($left_array, array($base_num), $right_array); } 6.二分查找算法(折半查找算法) function binsearch($x,$a){ $c=count($a); $lower=0; $high=$c-1; while($lower<=$high){ $middle=intval(($lower+$high)/2); if($a[$middle]>$x){ $high=$middle-1; } elseif($a[$middle]<$x){ $lower=$middle+1; } else{ return $middle; } } return false; } 7.PHP奇异算法 <?php function test(){ $a=1; $b=&$a; echo (++$a)+(++$a); } test(); PHP7以下的版本返回的是 6,PHP7版本返回5 ,还真的算奇异,个人底层算法差,认为是PHP7以下版本的BUG 8.字符集合:输入一个字符串,求出该字符串包含的字符集合,并按顺序排序(英文) function set($str){ //转化为数组 $arr = str_split($str); //去除重复 $arr = array_flip(array_flip($arr)); //排序 sort($arr); //返回字符串 return implode('', $arr); } 9.遍历一个文件下的所有文件和子文件夹下的文件 function AllFile($dir){ if($dh = opendir($dir)){ while (($file = readdir($dh)) !== false){ if($file !='..' && $file !='.'){ if(is_dir($dir.'/'.$file)){ AllFile($dir.'/'.$file); //如果判断还是文件,则递归 }else{ echo $file; //输出文件名 } } } } } 10.从一个标准的Url提取出文件的扩展名 function getExt($url) { $arr = parse_url($url); $file = basename($arr['path']);// basename函数返回路径中的文件名部分 $ext = explode('.', $file); return $ext[count($ext)-1]; } 11.有个人想上一个n级的台阶,每次只能迈1级或者迈2级台阶,问:这个人有多少种方法可以把台阶走完?例如:总共3级台阶,可以先迈1级再迈2级,或者先迈2级再迈1级,或者迈3次1级总共3中方式 function jieti($num){ //实际上是斐波那契数列 return $num<2?1:jieti($num-1)+jieti($num-2); } 12.请写一段PHP代码,确保多个进程同时写入同一个文件成功 <?php $fp = fopen("lock.txt","w+"); if (flock($fp,LOCK_EX)) { //获得写锁,写数据 fwrite($fp, "write something"); // 解除锁定 flock($fp, LOCK_UN); } else { echo "file is locking..."; } fclose($fp); ?> 13.无限级分类 function tree($arr,$pid=0,$level=0){ static $list = array(); foreach ($arr as $v) { //如果是顶级分类,则将其存到$list中,并以此节点为根节点,遍历其子节点 if ($v['pid'] == $pid) { $v['level'] = $level; $list[] = $v; tree($arr,$v['id'],$level+1); } } return $list; } 14.获取上个月第一天 和 最后一天 //获取上个月第一天 date('Y-m-01',strtotime('-1 month')); //获取上个月最后一天 date('Y-m-t',strtotime('-1 month')); 15.随机输入一个数字能查询到对应的数据区间 //把区间换成数组写法,用二分法查找区间 function binsearch($x,$a){ $c=count($a); $lower=0; $high=$c-1; while($lower<=$high){ $middle=intval(($lower+$high)/2); if($a[$middle]>=$x){ $high=$middle-1; }elseif($a[$middle]<=$x ){ $lower=$middle+1; } } return '在区间'.$a[$high].'到'.$a[$lower]; } $array = ['1','50','100','150','200','250','300']; $a = '120'; echo binsearch($a,$array); 以上就是php经典趣味算法的详细内容,更多内容请关注梦主博客以前发布的文章。...
技术教程 830次浏览 0条评论
2020-10-28
如何通过PHP实现Des加密算法代码实例

如何通过PHP实现Des加密算法代码实例

如何通过PHP实现Des加密算法代码实例 注:php7以上不支持了,因为php7去掉了某些函数, 另外变量的{}要改为[] <?php class Des { /** * 加密方法 * * @param string $str 需要加密的内容 * @param string $key 密钥 * @param bool $toBase64 是否base64 * return string */ public function encrypt($str, $key, $toBase64=true) { if ($str == "") { return ""; } if ($toBase64) { return base64_encode(self::_des($key,$str,1)); } return self::_des($key,$str,1); } /** * 解密方法 * * @param string $str 需要加密的内容 * @param string $key 密钥 * @param bool $toBase64 是否base64 * return string */ public function decrypt($str, $key, $toBase64=true) { if ($str == "") { return ""; } if ($toBase64) { return self::_des($key,base64_decode($str),0); } return self::_des($key,$str,0); } private function _des($key, $message, $encrypt, $mode=0, $iv=null) { $spfunction1 = array (0x1010400,0,0x10000,0x1010404,0x1010004,0x10404,0x4,0x10000,0x400,0x1010400,0x1010404,0x400,0x1000404,0x1010004,0x1000000,0x4,0x404,0x1000400,0x1000400,0x10400,0x10400,0x1010000,0x1010000,0x1000404,0x10004,0x1000004,0x1000004,0x10004,0,0x404,0x10404,0x1000000,0x10000,0x1010404,0x4,0x1010000,0x1010400,0x1000000,0x1000000,0x400,0x1010004,0x10000,0x10400,0x1000004,0x400,0x4,0x1000404,0x10404,0x1010404,0x10004,0x1010000,0x1000404,0x1000004,0x404,0x10404,0x1010400,0x404,0x1000400,0x1000400,0,0x10004,0x10400,0,0x1010004); $spfunction2 = array (-0x7fef7fe0,-0x7fff8000,0x8000,0x108020,0x100000,0x20,-0x7fefffe0,-0x7fff7fe0,-0x7fffffe0,-0x7fef7fe0,-0x7fef8000,-0x80000000,-0x7fff8000,0x100000,0x20,-0x7fefffe0,0x108000,0x100020,-0x7fff7fe0,0,-0x80000000,0x8000,0x108020,-0x7ff00000,0x100020,-0x7fffffe0,0,0x108000,0x8020,-0x7fef8000,-0x7ff00000,0x8020,0,0x108020,-0x7fefffe0,0x100000,-0x7fff7fe0,-0x7ff00000,-0x7fef8000,0x8000,-0x7ff00000,-0x7fff8000,0x20,-0x7fef7fe0,0x108020,0x20,0x8000,-0x80000000,0x8020,-0x7fef8000,0x100000,-0x7fffffe0,0x100020,-0x7fff7fe0,-0x7fffffe0,0x100020,0x108000,0,-0x7fff8000,0x8020,-0x80000000,-0x7fefffe0,-0x7fef7fe0,0x108000); $spfunction3 = array (0x208,0x8020200,0,0x8020008,0x8000200,0,0x20208,0x8000200,0x20008,0x8000008,0x8000008,0x20000,0x8020208,0x20008,0x8020000,0x208,0x8000000,0x8,0x8020200,0x200,0x20200,0x8020000,0x8020008,0x20208,0x8000208,0x20200,0x20000,0x8000208,0x8,0x8020208,0x200,0x8000000,0x8020200,0x8000000,0x20008,0x208,0x20000,0x8020200,0x8000200,0,0x200,0x20008,0x8020208,0x8000200,0x8000008,0x200,0,0x8020008,0x8000208,0x20000,0x8000000,0x8020208,0x8,0x20208,0x20200,0x8000008,0x8020000,0x8000208,0x208,0x8020000,0x20208,0x8,0x8020008,0x20200); $spfunction4 = array (0x802001,0x2081,0x2081,0x80,0x802080,0x800081,0x800001,0x2001,0,0x802000,0x802000,0x802081,0x81,0,0x800080,0x800001,0x1,0x2000,0x800000,0x802001,0x80,0x800000,0x2001,0x2080,0x800081,0x1,0x2080,0x800080,0x2000,0x802080,0x802081,0x81,0x800080,0x800001,0x802000,0x802081,0x81,0,0,0x802000,0x2080,0x800080,0x800081,0x1,0x802001,0x2081,0x2081,0x80,0x802081,0x81,0x1,0x2000,0x800001,0x2001,0x802080,0x800081,0x2001,0x2080,0x800000,0x802001,0x80,0x800000,0x2000,0x802080); $spfunction5 = array (0x100,0x2080100,0x2080000,0x42000100,0x80000,0x100,0x40000000,0x2080000,0x40080100,0x80000,0x2000100,0x40080100,0x42000100,0x42080000,0x80100,0x40000000,0x2000000,0x40080000,0x40080000,0,0x40000100,0x42080100,0x42080100,0x2000100,0x42080000,0x40000100,0,0x42000000,0x2080100,0x2000000,0x42000000,0x80100,0x80000,0x42000100,0x100,0x2000000,0x40000000,0x2080000,0x42000100,0x40080100,0x2000100,0x40000000,0x42080000,0x2080100,0x40080100,0x100,0x2000000,0x42080000,0x42080100,0x80100,0x42000000,0x42080100,0x2080000,0,0x40080000,0x42000000,0x80100,0x2000100,0x40000100,0x80000,0,0x40080000,0x2080100,0x40000100); $spfunction6 = array (0x20000010,0x20400000,0x4000,0x20404010,0x20400000,0x10,0x20404010,0x400000,0x20004000,0x404010,0x400000,0x20000010,0x400010,0x20004000,0x20000000,0x4010,0,0x400010,0x20004010,0x4000,0x404000,0x20004010,0x10,0x20400010,0x20400010,0,0x404010,0x20404000,0x4010,0x404000,0x20404000,0x20000000,0x20004000,0x10,0x20400010,0x404000,0x20404010,0x400000,0x4010,0x20000010,0x400000,0x20004000,0x20000000,0x4010,0x20000010,0x20404010,0x404000,0x20400000,0x404010,0x20404000,0,0x20400010,0x10,0x4000,0x20400000,0x404010,0x4000,0x400010,0x20004010,0,0x20404000,0x20000000,0x400010,0x20004010); $spfunction7 = array (0x200000,0x4200002,0x4000802,0,0x800,0x4000802,0x200802,0x4200800,0x4200802,0x200000,0,0x4000002,0x2,0x4000000,0x4200002,0x802,0x4000800,0x200802,0x200002,0x4000800,0x4000002,0x4200000,0x4200800,0x200002,0x4200000,0x800,0x802,0x4200802,0x200800,0x2,0x4000000,0x200800,0x4000000,0x200800,0x200000,0x4000802,0x4000802,0x4200002,0x4200002,0x2,0x200002,0x4000000,0x4000800,0x200000,0x4200800,0x802,0x200802,0x4200800,0x802,0x4000002,0x4200802,0x4200000,0x200800,0,0x2,0x4200802,0,0x200802,0x4200000,0x800,0x4000002,0x4000800,0x800,0x200002); $spfunction8 = array (0x10001040,0x1000,0x40000,0x10041040,0x10000000,0x10001040,0x40,0x10000000,0x40040,0x10040000,0x10041040,0x41000,0x10041000,0x41040,0x1000,0x40,0x10040000,0x10000040,0x10001000,0x1040,0x41000,0x40040,0x10040040,0x10041000,0x1040,0,0,0x10040040,0x10000040,0x10001000,0x41040,0x40000,0x41040,0x40000,0x10041000,0x1000,0x40,0x10040040,0x1000,0x41040,0x10001000,0x40,0x10000040,0x10040000,0x10040040,0x10000000,0x40000,0x10001040,0,0x10041040,0x40040,0x10000040,0x10040000,0x10001000,0x10001040,0,0x10041040,0x41000,0x41000,0x1040,0x1040,0x40040,0x10000000,0x10041000); $masks = array (4294967295,2147483647,1073741823,536870911,268435455,134217727,67108863,33554431,16777215,8388607,4194303,2097151,1048575,524287,262143,131071,65535,32767,16383,8191,4095,2047,1023,511,255,127,63,31,15,7,3,1,0); $keys = self::_createKeys ($key); $m=0; $len = strlen($message); $chunk = 0; $iterations = ((count($keys) == 32) ? 3 : 9); if ($iterations == 3) {$looping = (($encrypt) ? array (0, 32, 2) : array (30, -2, -2));} else {$looping = (($encrypt) ? array (0, 32, 2, 62, 30, -2, 64, 96, 2) : array (94, 62, -2, 32, 64, 2, 30, -2, -2));} $message .= (chr(0) . chr(0) . chr(0) . chr(0) . chr(0) . chr(0) . chr(0) . chr(0)); $result = ""; $tempresult = ""; if ($mode == 1) { $cbcleft = (ord($iv[$m++]) << 24) | (ord($iv[$m++]) << 16) | (ord($iv[$m++]) << 8) | ord($iv[$m++]); $cbcright = (ord($iv[$m++]) << 24) | (ord($iv[$m++]) << 16) | (ord($iv[$m++]) << 8) | ord($iv[$m++]); $m=0; } while ($m < $len) { $left = (ord($message[$m++]) << 24) | (ord($message[$m++]) << 16) | (ord($message[$m++]) << 8) | ord($message[$m++]); $right = (ord($message[$m++]) << 24) | (ord($message[$m++]) << 16) | (ord($message[$m++]) << 8) | ord($message[$m++]); if ($mode == 1) {if ($encrypt) {$left ^= $cbcleft; $right ^= $cbcright;} else {$cbcleft2 = $cbcleft; $cbcright2 = $cbcright; $cbcleft = $left; $cbcright = $right;}} $temp = (($left >> 4 & $masks[4]) ^ $right) & 0x0f0f0f0f; $right ^= $temp; $left ^= ($temp << 4); $temp = (($left >> 16 & $masks[16]) ^ $right) & 0x0000ffff; $right ^= $temp; $left ^= ($temp << 16); $temp = (($right >> 2 & $masks[2]) ^ $left) & 0x33333333; $left ^= $temp; $right ^= ($temp << 2); $temp = (($right >> 8 & $masks[8]) ^ $left) & 0x00ff00ff; $left ^= $temp; $right ^= ($temp << 8); $temp = (($left >> 1 & $masks[1]) ^ $right) & 0x55555555; $right ^= $temp; $left ^= ($temp << 1); $left = (($left << 1) | ($left >> 31 & $masks[31])); $right = (($right << 1) | ($right >> 31 & $masks[31])); for ($j=0; $j<$iterations; $j+=3) { $endloop = $looping[$j+1]; $loopinc = $looping[$j+2]; for ($i=$looping[$j]; $i!=$endloop; $i+=$loopinc) { $right1 = $right ^ $keys[$i]; $right2 = (($right >> 4 & $masks[4]) | ($right << 28)) ^ $keys[$i+1]; $temp = $left; $left = $right; $right = $temp ^ ($spfunction2[($right1 >> 24 & $masks[24]) & 0x3f] | $spfunction4[($right1 >> 16 & $masks[16]) & 0x3f] | $spfunction6[($right1 >> 8 & $masks[8]) & 0x3f] | $spfunction8[$right1 & 0x3f] | $spfunction1[($right2 >> 24 & $masks[24]) & 0x3f] | $spfunction3[($right2 >> 16 & $masks[16]) & 0x3f] | $spfunction5[($right2 >> 8 & $masks[8]) & 0x3f] | $spfunction7[$right2 & 0x3f]); } $temp = $left; $left = $right; $right = $temp; } $left = (($left >> 1 & $masks[1]) | ($left << 31)); $right = (($right >> 1 & $masks[1]) | ($right << 31)); $temp = (($left >> 1 & $masks[1]) ^ $right) & 0x55555555; $right ^= $temp; $left ^= ($temp << 1); $temp = (($right >> 8 & $masks[8]) ^ $left) & 0x00ff00ff; $left ^= $temp; $right ^= ($temp << 8); $temp = (($right >> 2 & $masks[2]) ^ $left) & 0x33333333; $left ^= $temp; $right ^= ($temp << 2); $temp = (($left >> 16 & $masks[16]) ^ $right) & 0x0000ffff; $right ^= $temp; $left ^= ($temp << 16); $temp = (($left >> 4 & $masks[4]) ^ $right) & 0x0f0f0f0f; $right ^= $temp; $left ^= ($temp << 4); if ($mode == 1) {if ($encrypt) {$cbcleft = $left; $cbcright = $right;} else {$left ^= $cbcleft2; $right ^= $cbcright2;}} $tempresult .= (chr($left>>24 & $masks[24]) . chr(($left>>16 & $masks[16]) & 0xff) . chr(($left>>8 & $masks[8]) & 0xff) . chr($left & 0xff) . chr($right>>24 & $masks[24]) . chr(($right>>16 & $masks[16]) & 0xff) . chr(($right>>8 & $masks[8]) & 0xff) . chr($right & 0xff)); $chunk += 8; if ($chunk == 512) {$result .= $tempresult; $tempresult = ""; $chunk = 0;} } return ($result . $tempresult); } private function _createKeys ($key) { $pc2bytes0 = array (0,0x4,0x20000000,0x20000004,0x10000,0x10004,0x20010000,0x20010004,0x200,0x204,0x20000200,0x20000204,0x10200,0x10204,0x20010200,0x20010204); $pc2bytes1 = array (0,0x1,0x100000,0x100001,0x4000000,0x4000001,0x4100000,0x4100001,0x100,0x101,0x100100,0x100101,0x4000100,0x4000101,0x4100100,0x4100101); $pc2bytes2 = array (0,0x8,0x800,0x808,0x1000000,0x1000008,0x1000800,0x1000808,0,0x8,0x800,0x808,0x1000000,0x1000008,0x1000800,0x1000808); $pc2bytes3 = array (0,0x200000,0x8000000,0x8200000,0x2000,0x202000,0x8002000,0x8202000,0x20000,0x220000,0x8020000,0x8220000,0x22000,0x222000,0x8022000,0x8222000); $pc2bytes4 = array (0,0x40000,0x10,0x40010,0,0x40000,0x10,0x40010,0x1000,0x41000,0x1010,0x41010,0x1000,0x41000,0x1010,0x41010); $pc2bytes5 = array (0,0x400,0x20,0x420,0,0x400,0x20,0x420,0x2000000,0x2000400,0x2000020,0x2000420,0x2000000,0x2000400,0x2000020,0x2000420); $pc2bytes6 = array (0,0x10000000,0x80000,0x10080000,0x2,0x10000002,0x80002,0x10080002,0,0x10000000,0x80000,0x10080000,0x2,0x10000002,0x80002,0x10080002); $pc2bytes7 = array (0,0x10000,0x800,0x10800,0x20000000,0x20010000,0x20000800,0x20010800,0x20000,0x30000,0x20800,0x30800,0x20020000,0x20030000,0x20020800,0x20030800); $pc2bytes8 = array (0,0x40000,0,0x40000,0x2,0x40002,0x2,0x40002,0x2000000,0x2040000,0x2000000,0x2040000,0x2000002,0x2040002,0x2000002,0x2040002); $pc2bytes9 = array (0,0x10000000,0x8,0x10000008,0,0x10000000,0x8,0x10000008,0x400,0x10000400,0x408,0x10000408,0x400,0x10000400,0x408,0x10000408); $pc2bytes10 = array (0,0x20,0,0x20,0x100000,0x100020,0x100000,0x100020,0x2000,0x2020,0x2000,0x2020,0x102000,0x102020,0x102000,0x102020); $pc2bytes11 = array (0,0x1000000,0x200,0x1000200,0x200000,0x1200000,0x200200,0x1200200,0x4000000,0x5000000,0x4000200,0x5000200,0x4200000,0x5200000,0x4200200,0x5200200); $pc2bytes12 = array (0,0x1000,0x8000000,0x8001000,0x80000,0x81000,0x8080000,0x8081000,0x10,0x1010,0x8000010,0x8001010,0x80010,0x81010,0x8080010,0x8081010); $pc2bytes13 = array (0,0x4,0x100,0x104,0,0x4,0x100,0x104,0x1,0x5,0x101,0x105,0x1,0x5,0x101,0x105); $masks = array (4294967295,2147483647,1073741823,536870911,268435455,134217727,67108863,33554431,16777215,8388607,4194303,2097151,1048575,524287,262143,131071,65535,32767,16383,8191,4095,2047,1023,511,255,127,63,31,15,7,3,1,0); $iterations = ((strlen($key) >= 24) ? 3 : 1); $keys = array (); $shifts = array (0, 0, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1, 1, 0); $m=0; $n=0; for ($j=0; $j<$iterations; $j++) { $left = (ord($key[$m++]) << 24) | (ord($key[$m++]) << 16) | (ord($key[$m++]) << 8) | ord($key[$m++]); $right = (ord($key[$m++]) << 24) | (ord($key[$m++]) << 16) | (ord($key[$m++]) << 8) | ord($key[$m++]); $temp = (($left >> 4 & $masks[4]) ^ $right) & 0x0f0f0f0f; $right ^= $temp; $left ^= ($temp << 4); $temp = (($right >> 16 & $masks[16]) ^ $left) & 0x0000ffff; $left ^= $temp; $right ^= ($temp << -16); $temp = (($left >> 2 & $masks[2]) ^ $right) & 0x33333333; $right ^= $temp; $left ^= ($temp << 2); $temp = (($right >> 16 & $masks[16]) ^ $left) & 0x0000ffff; $left ^= $temp; $right ^= ($temp << -16); $temp = (($left >> 1 & $masks[1]) ^ $right) & 0x55555555; $right ^= $temp; $left ^= ($temp << 1); $temp = (($right >> 8 & $masks[8]) ^ $left) & 0x00ff00ff; $left ^= $temp; $right ^= ($temp << 8); $temp = (($left >> 1 & $masks[1]) ^ $right) & 0x55555555; $right ^= $temp; $left ^= ($temp << 1); $temp = ($left << 8) | (($right >> 20 & $masks[20]) & 0x000000f0); $left = ($right << 24) | (($right << 8) & 0xff0000) | (($right >> 8 & $masks[8]) & 0xff00) | (($right >> 24 & $masks[24]) & 0xf0); $right = $temp; for ($i=0; $i < count($shifts); $i++) { if ($shifts[$i] > 0) { $left = (($left << 2) | ($left >> 26 & $masks[26])); $right = (($right << 2) | ($right >> 26 & $masks[26])); } else { $left = (($left << 1) | ($left >> 27 & $masks[27])); $right = (($right << 1) | ($right >> 27 & $masks[27])); } $left = $left & -0xf; $right = $right & -0xf; $lefttemp = $pc2bytes0[$left >> 28 & $masks[28]] | $pc2bytes1[($left >> 24 & $masks[24]) & 0xf] | $pc2bytes2[($left >> 20 & $masks[20]) & 0xf] | $pc2bytes3[($left >> 16 & $masks[16]) & 0xf] | $pc2bytes4[($left >> 12 & $masks[12]) & 0xf] | $pc2bytes5[($left >> 8 & $masks[8]) & 0xf] | $pc2bytes6[($left >> 4 & $masks[4]) & 0xf]; $righttemp = $pc2bytes7[$right >> 28 & $masks[28]] | $pc2bytes8[($right >> 24 & $masks[24]) & 0xf] | $pc2bytes9[($right >> 20 & $masks[20]) & 0xf] | $pc2bytes10[($right >> 16 & $masks[16]) & 0xf] | $pc2bytes11[($right >> 12 & $masks[12]) & 0xf] | $pc2bytes12[($right >> 8 & $masks[8]) & 0xf] | $pc2bytes13[($right >> 4 & $masks[4]) & 0xf]; $temp = (($righttemp >> 16 & $masks[16]) ^ $lefttemp) & 0x0000ffff; $keys[$n++] = $lefttemp ^ $temp; $keys[$n++] = $righttemp ^ ($temp << 16); } } return $keys; } } // 使用方式 $Des = new Des(); $string = 'hello leven'; $key = '123456'; $encode = $Des->encrypt($string,$key,true); $decode = $Des->decrypt($encode,$key,true); echo $encode; echo "<br />"; echo $decode; ?> 另一个DES加密算法 class CryptDes { function __construct(){ $this->key = 'codelovers'; //密钥 $this->iv = '15548632'; //偏移量 } /* * 加密 */ function encrypt($input){ $size = mcrypt_get_block_size(MCRYPT_DES,MCRYPT_MODE_CBC); //3DES加密将MCRYPT_DES改为MCRYPT_3DES $input = $this->pkcs5_pad($input, $size); //如果采用PaddingPKCS7,请更换成PaddingPKCS7方法。 $key = str_pad($this->key,8,'0'); //3DES加密将8改为24 $td = mcrypt_module_open(MCRYPT_DES, '', MCRYPT_MODE_CBC, ''); if( $this->iv == '' ) { $iv = @mcrypt_create_iv (mcrypt_enc_get_iv_size($td), MCRYPT_RAND); } else { $iv = $this->iv; } @mcrypt_generic_init($td, $key, $iv); $data = mcrypt_generic($td, $input); mcrypt_generic_deinit($td); mcrypt_module_close($td); $data = base64_encode($data);//如需转换二进制可改成 bin2hex 转换 return $data; } /* * 解密 */ function decrypt($encrypted){ $encrypted = base64_decode($encrypted); //如需转换二进制可改成 bin2hex 转换 $key = str_pad($this->key,8,'0'); //3DES加密将8改为24 $td = mcrypt_module_open(MCRYPT_DES,'',MCRYPT_MODE_CBC,'');//3DES加密将MCRYPT_DES改为MCRYPT_3DES if( $this->iv == '' ) { $iv = @mcrypt_create_iv (mcrypt_enc_get_iv_size($td), MCRYPT_RAND); } else { $iv = $this->iv; } $ks = mcrypt_enc_get_key_size($td); @mcrypt_generic_init($td, $key, $iv); $decrypted = mdecrypt_generic($td, $encrypted); mcrypt_generic_deinit($td); mcrypt_module_close($td); $y=$this->pkcs5_unpad($decrypted); return $y; } function pkcs5_pad ($text, $blocksize) { $pad = $blocksize - (strlen($text) % $blocksize); return $text . str_repeat(chr($pad), $pad); } function pkcs5_unpad($text){ $pad = ord($text{strlen($text)-1}); if ($pad > strlen($text)) { return false; } if (strspn($text, chr($pad), strlen($text) - $pad) != $pad){ return false; } return substr($text, 0, -1 * $pad); } function PaddingPKCS7($data) { $block_size = mcrypt_get_block_size(MCRYPT_DES, MCRYPT_MODE_CBC);//3DES加密将MCRYPT_DES改为MCRYPT_3DES $padding_char = $block_size - (strlen($data) % $block_size); $data .= str_repeat(chr($padding_char),$padding_char); return $data; } } 用法如下: $str = 'www.jb51.net'; $des = new CryptDes(); $mres = $des->encrypt($str); //加密 echo $mres."<br/>"; $jres = $des->decrypt($mres); //解密 echo $jres."<br/>"; 以上就是本文的全部内容,希望对大家的学习有所帮助,也希望大家多多支持梦主博客。...
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