Examples of common PHP Algorithms and Data Structures

: This article mainly introduces common PHP Algorithms and Data Structure examples. For more information about PHP tutorials, see.

 "; // Sort // common sorting algorithms // --------------------------------------------- // bubble sorting function BubbleSort ($ arr) {$ length = count ($ arr ); if ($ length <= 1) {return $ arr;} for ($ I = 0; $ I <$ length; $ I ++) {for ($ j = $ length; $ 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 sorting: '; echo implode ('', BubbleSort ($ arr ))."
"; // Quick sorting function QSort ($ arr) {$ length = count ($ arr); if ($ length <= 1) {return $ arr ;} $ outputs = $ arr [0]; // pivot $ left_arr = array (); $ right_arr = array (); for ($ I = 1; $ I <$ length; $ I ++) {// note that $ I starts from 1 and 0 is the pivot if ($ arr [$ I] <= $ scheme) {$ left_arr [] = $ arr [$ I];} else {$ right_arr [] = $ arr [$ I] ;}}$ left_arr = QSort ($ left_arr ); // recursive sorting of the left half $ right_arr = QSort ($ right_arr); // recursive sorting of the right half return array_merge ($ left_arr, array ($ weight), $ right_arr ); // merge the left half, pivot, and right half} echo "quick sorting:"; echo implode ('', QSort ($ arr ))."
"; // 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 sorting:"; echo implode ('', SelectSort ($ arr ))."
"; // Insert sorting 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 order: '; echo implode ('', insertSort ($ arr ))."
"; // --------------------------------------- // Common search algorithms // ------------------------------------------- // binary search function binary_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 query {$ key} location:"; echo binary_search (QSort ($ arr), $ key); // sequential query 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"
Location of the {$ key} in the regular order: "; echo SqSearch ($ arr, $ key ); // FUNCTIONS // common data structures // ------------------------------------------- // function delete_array_element ($ arr, $ pos) {$ length = count ($ arr ); if ($ pos <1 | $ pos> $ length) {return "an error occurred while deleting the location! ";}For ($ I = $ pos-1; $ I <$ length-1; $ I ++) {$ arr [$ I] = $ arr [$ I + 1];} array_pop ($ arr); return $ arr ;}$ pos = 3; echo"
Except for the element at the position {$ pos}: "; echo implode ('', delete_array_element ($ arr, $ pos ))."
";/*** Class Node * PHP simulates the basic operation of the linked list */class Node {public $ data =''; public $ next = null ;} // initialize function init ($ linkList) {$ linkList-> data = 0; // records the length of the linked list $ linkList-> next = null ;} // create the function createHead (& $ linkList, $ length) {for ($ I = 0; $ I <$ length; $ I ++) {$ newNode = new Node (); $ newNode-> data = $ I; $ newNode-> next = $ linkList-> next; // because the object in PHP is referenced, you do not need to use "&" $ linkList-> next = $ newNode; $ linkList-> data ++. ;}} // Create the linked 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 function insert ($ linkList, $ pos, $ elem) {if ($ pos <1 & $ pos> $ linkList-> data + 1) {echo "insertion location 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 function delete ($ linkList, $ pos) {if ($ pos <1 & $ pos> $ linkList-> data + 1) element at the specified position) {echo "location 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 --;} // function show ($ linkList) {$ p = $ linkList-> next; while ($ p! = Null) {echo $ p-> data. ""; $ p = $ p-> next;} echo'
';}$ LinkList = new Node (); init ($ linkList); // initialize createTail ($ linkList, 10); // Create a linked list show ($ linkList) by means of the end plug-in ); // Print the chain table insert ($ linkList, 3, 'A'); // insert show ($ linkList); delete ($ linkList, 3 ); // delete show ($ linkList);/*** Class Stack * simulate basic operations of the sequence Stack with PHP */class Stack {// use the default value to initialize the Stack directly, you can also use constructor to initialize the stack private $ top =-1; private $ maxSize = 5; private $ stack = array (); // public function push ($ elem) of the inbound stack) {if ($ this-> top >=$ this-> maxSize-1 ){ Echo "the stack is full!
"; Return ;}$ this-> top ++; $ this-> stack [$ this-> top] = $ elem ;}// 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 the public function show () {for ($ I = $ this-> top; $ I >= 0; $ I --) {echo $ this-> stack [$ I]. "";} echo"
";}}$ 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-> show ();

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