Common algorithms and data structures in PHP

This article mainly introduces PHP common algorithms and data structure, interested in the small partner reference, I hope to help you.

</pre><pre name= "code" class= "PHP" ><?php/** * Created by Phpstorm.  * User:qishou * date:15-8-2 * time: Morning 9:12 */header ("Content-type:text/html;charset=utf-8");  $arr = Array (3,5,8,4,9,6,1,7,2); echo Implode ("", $arr). "  <br/> "; ---------------------------------------//Common sort algorithm//---------------------------------------//bubble sort function Bub      Blesort ($arr) {$length = count ($arr);      if ($length <=1) {return $arr;                  } for ($i =0; $i < $length; $i + +) {for ($j = $length-1; $j > $i; $j-) {if ($arr [$j]< $arr [$j-1]) {                  $tmp = $arr [$j];                  $arr [$j] = $arr [$j-1];              $arr [$j-1] = $tmp;  }}} return $arr;  } echo ' bubble sort: '; Echo Implode (", Bubblesort ($arr))."  <br/> ";      Quick Sort function QSort ($arr) {$length = count ($arr);      if ($length <=1) {return $arr;      } $pivot = $arr [0];//pivot $left _arr = array (); $right _arr = ARray ();          for ($i =1; $i < $length; $i + +) {//note $i starting from 1 0 is the pivot if ($arr [$i]<= $pivot) {$left _arr[] = $arr [$i];          }else{$right _arr[] = $arr [$i]; }} $left _arr = QSort ($left _arr);//recursive sort left half $right _arr = QSort ($right _arr);//recursive sort right half return Array_merge ($  Left_arr,array ($pivot), $right _arr);//merge left half, Pivot, right half part} echo "Quick sort:"; Echo Implode (", QSort ($arr))."  <br/> ";      Select sort (unstable) function Selectsort ($arr) {$length = count ($arr);      if ($length <=1) {return $arr;          } for ($i =0; $i < $length; $i + +) {$min = $i;              for ($j = $i +1; $j < $length; $j + +) {if ($arr [$j]< $arr [$min]) {$min = $j;              }} if ($i! = $min) {$tmp = $arr [$i];              $arr [$i] = $arr [$min];          $arr [$min] = $tmp;  }} return $arr;  } echo "select Sort:"; Echo Implode (", Selectsort ($arr))."  <br/> ";  Insert Sort function Insertsort ($arr) {    $length = count ($arr);      if ($length <=1) {return $arr;          } for ($i =1; $i < $length; $i + +) {$x = $arr [$i];          $j = $i-1;              while ($x < $arr [$j] && $j >=0) {$arr [$j +1] = $arr [$j];          $j--;      } $arr [$j +1] = $x;  } return $arr;  } echo ' Insert sort: '; Echo Implode (", Insertsort ($arr))."  <br/> "; ---------------------------------------//Common find algorithm//---------------------------------------//Two points find function bin          Ary_search ($arr, $low, $high, $key) {while ($low <= $high) {$mid = Intval (($low + $high)/2);          if ($key = = $arr [$mid]) {return $mid +1;          }elseif ($key < $arr [$mid]) {$high = $mid-1;          }elseif ($key > $arr [$mid]) {$low = $mid +1;  }} return-1;  } $key = 6;  echo "binary find {$key} location:";  Echo Binary_search (QSort ($arr), 0,8, $key);    Order Lookup Function Sqsearch ($arr, $key) {$length = count ($arr);  for ($i =0; $i < $length; $i + +) {if ($key = = $arr [$i]) {return $i +1;  }} return-1;  } $key = 8;  echo "<br/> Order general find {$key} location:";  Echo Sqsearch ($arr, $key); ---------------------------------------//Common data structure//---------------------------------------///Linear table deletion (array implementation) Func      tion Delete_array_element ($arr, $pos) {$length = count ($arr);      if ($pos <1 | | $pos > $length) {return "Error deleting location!";      } for ($i = $pos-1; $i < $length-1; $i + +) {$arr [$i] = $arr [$i +1];      } array_pop ($arr);  return $arr;  } $pos = 3;  echo "<br/> In addition to the element {$pos} at position:"; Echo Implode (", Delete_array_element ($arr, $pos))."  <br/> ";      /** * Class Node * PHP analog List of basic operations */class node{public $data = ";  public $next = null;  }//Initialize function init ($linkList) {$linkList->data = 0;//to record the length of the linked list $linkList->next = null;    }//Head interpolation create List function Createhead (& $linkList, $length) {for ($i =0; $i < $length; $i + +) {      $newNode = new Node ();          $newNode->data = $i;          $newNode->next = $linkList->next;//Because the object itself in PHP is a reference so no longer available "&" $linkList->next = $newNode;      $linkList->data++;      }}//tail interpolation to create a list function Createtail (& $linkList, $length) {$r = $linkList;          for ($i =0; $i < $length; $i + +) {$newNode = new Node ();          $newNode->data = $i;          $newNode->next = $r->next;          $r->next = $newNode;          $r = $newNode;      $linkList->data++;          }}//insert the specified element function insert ($linkList, $pos, $elem) at the specified location {if ($pos <1 && $pos > $linkList->data+1) { echo "Insertion position Error!      ";      } $p = $linkList;      for ($i =1; $i < $pos; $i + +) {$p = $p->next;      } $newNode = new Node ();      $newNode->data = $elem;      $newNode->next = $p->next;  $p->next = $newNode; }//Delete the element at the specified location function delete ($linkList, $pos) {if ($pos <1 && $pos > $linkList->data+1{echo "position does not exist!)      ";      } $p = $linkList;      for ($i =1; $i < $pos; $i + +) {$p = $p->next;      } $q = $p->next;      $p->next = $q->next;      Unset ($q);  $linkList->data--;      }//Output list data function Show ($linkList) {$p = $linkList->next; while ($p!=null) {echo $p->data. "          ";      $p = $p->next;  } echo ' <br/> ';  } $linkList = new Node (); Init ($linkList);//Initialize Createtail ($linkList, 10);//tail interpolation to create a linked list show ($linkList);//Print out the list insert ($linkList, 3, ' a ');//Insert Show  ($linkList);  Delete ($linkList, 3);//Remove show ($linkList);      /** * Class stack * uses PHP to simulate the basic operation of the sequence stack */class stack{//with default values to initialize the stack directly, you can also use the constructor method to initialize the stack private $top =-1;      Private $maxSize = 5;      Private $stack = Array (); into the stack public function push ($elem) {if ($this->top >= $this->maxsize-1) {echo "stack is full!)              <br/> ";          Return          } $this->top++;      $this->stack[$this->top] = $elem;}//out-Stack public function pop () {if ($this->top = =-1) {echo "stack is empty!)              ";          return;          } $elem = $this->stack[$this->top];          unset ($this->stack[$this->top]);          $this->top--;      return $elem; }//Print stack public function show () {for ($i = $this->top; $i >=0; $i-) {echo $this->stack[$i ]."          ";      } echo "<br/>";  }} $stack = new stack ();  $stack->push (3);  $stack->push (5);  $stack->push (8);  $stack->push (7);  $stack->push (9);  $stack->push (2);  $stack->show ();  $stack->pop ();  $stack->pop ();  $stack->pop ();  $stack->show ();      /** * Class Deque * Use PHP to implement bidirectional queue */class deque{Private $queue = Array ();      Public Function AddFirst ($item) {//Head queue Array_unshift ($this->queue, $item);      } Public Function AddLast ($item) {//Tail Array_push ($this->queue, $item); } Public Function removeFirst () {//head-out Team Array_shift ($this->queue);      } public Function Removelast () {//Tail out Team Array_pop ($this->queue); Public function Show () {//print foreach ($this->queue as $item) {echo $item.          ";      } echo "<br/>";  }} $deque = new deque ();  $deque->addfirst (2);  $deque->addlast (3);  $deque->addlast (4);  $deque->addfirst (5);  $deque->show ();      PHP solves Joseph Ring Problem//Method one function joseph_ring ($n, $m) {$arr = range (1, $n);      $i = 0;          while (count ($arr) >1) {$i = $i +1;          $head = Array_shift ($arr);          if ($i% $m! = 0) {//If not re-press into the array array_push ($arr, $head);  }} return $arr [0];      }//Method two function Joseph_ring2 ($n, $m) {$r = 0;      for ($i =2; $i <= $n; $i + +) {$r = ($r + $m)% $i;  } return $r + 1; } echo "<br/>". Joseph_ring (60,5). "  <br/> "; echo "<br/>". Joseph_ring2 (60,5). " <br/> ";