PHP Data Structure 2: PHP implementation of sequence tables in linear tables

Linear table (LinearList): is composed of n (n limit 0) data elements (nodes) a1, a2 ,... An finite sequence. All nodes in the sequence have the same data type. N is the length of a linear table.

Linear table

(1) basic features: the most basic, simple, and commonly used data structure in this structure:

1. there is a unique data element called "first;

2. there is a unique data element called "last;

3. except the first element, each element has a unique direct precursor;

4. except for the last element, each element has a unique direct successor.

(2) definition:

Linear table (Linear List): is composed of n (n limit 0) data elements (nodes) a1, a2 ,... An finite sequence. All nodes in the sequence have the same data type. N is the length of a linear table.

When n = 0, it is called an empty table.

When n> 0, the non-empty linear table is recorded as: (a1, a2 ,... An)
A1 is the first (first) node of a linear table, and an is the last (last) node of a linear table. (3) sequential storage of linear tables: nodes of linear tables are stored in a group of sequential storage units in a logical order. A linear table stored in this way is called a sequential table.

Features of a linear table stored in sequence:

1. the logical sequence of a linear table is the same as that of a physical table;

2. the relationship between data elements is reflected by the "physical location adjacent" of the elements in the computer.

PHP implementation of sequence tables in linear tables

 

 Oll = $ oll;}/*** clear sequence table * @ return void */public function _ destruct () {foreach ($ this-> oll as $ key = >$ value) {unset ($ this-> oll [$ key]);} /*** determine whether the sequence table is EMPTY * @ return boolean returns true if it is null; otherwise, false is returned. **/public function isEmpty () {if (count ($ this-> oll)> 0) {return false;} else {return true ;}} /*** return the length of the sequence table * @ return int **/public function getLength () {return count ($ this-> oll );} /*** return the element whose subscript is $ key in the sequence table ** @ param mixed $ Key: subscript * @ return mixed **/public function getElement ($ key) {return $ this-> oll [$ key];} /*** return the position of an element in the sequence table ** @ param mixed $ value the value of an element in the sequence table * @ return int starts from 1, if-1 is returned, this element does not exist. **/public function getElementPosition ($ value) {$ I = 0; foreach ($ this-> oll as $ val) {$ I ++; if (strcmp ($ value, $ val) === 0) {return $ I ;}} return-1 ;} /*** return the direct precursor element of an element in the sequence table ** @ param mixed $ value the value of an element in the sequence table * @ param bool $ tag if $ If the value is the lower mark, it is 1. if $ value is the element value, it is 2 * @ return array ('value' => ...) directly precursor element value, array ('key' => ...) direct precursor element subscript **/public function getElementPredecessorr ($ value, $ tag = 1) {$ I = 0; foreach ($ this-> oll as $ key => $ val) {$ I ++; if ($ tag = 1) {if (strcmp ($ key, $ value) = 0) {if ($ I = 1) {return false;} prev ($ this-> oll); return array ('value' => current ($ this-> oll ), 'key' => key ($ this-> oll) ;}} if ($ tag = 2) {if (strcmp ($ val, $ v Alue) === 0) {if ($ I = 1) {return false;} prev ($ this-> oll ); return array ('value' => current ($ this-> oll), 'key' => key ($ this-> oll ));}}}} /*** return the direct successor element of an element ** @ param mixed $ value the value of an element in the sequence table * @ param bool $ tag: 1 if $ value is the lower mark, if $ value is an element value, it is 2 * @ return array ('value' => ...) directly successor element value, array ('key' => ...) directly subscripts to the successor element **/public function getElementSubsequence ($ value, $ tag = 1) {$ I = 0; $ len = count ($ this-> oll); fo Reach ($ this-> oll as $ key => $ val) {$ I ++; if ($ tag = 1) {if (strcmp ($ key, $ value) = 0) {if ($ I = $ len) {return false;} return array ('value' => current ($ this-> oll ), 'key' => key ($ this-> oll) ;}} if ($ tag = 2) {if (strcmp ($ val, $ value) = 0) {if ($ I ==$ len) {return false;} return array ('value' => current ($ this-> oll ), 'key' => key ($ this-> oll) ;}} return false ;} /*** insert a new node at the specified position ** @ param mixed $ p new node insertion position, starting from 1 * @ param mixed $ Value the value of the new node in the ordered table * @ param mixed $ subscript of the new node in the key ordered table * @ param bool $ tag specifies whether the subscript of the new node is used. 1 indicates the Default subscript, 2 indicates that the specified subscript * @ return bool returns true if insertion is successful, and false if insertion fails. **/public function getInsertElement ($ p, $ value, $ key = null, $ tag = 1) {$ p = (int) $ p; $ len = count ($ this-> oll); $ oll = array (); $ I = 0; if ($ p> $ len | $ p <1) {return false;} foreach ($ this-> oll as $ k =>$ v) {$ I ++; if ($ I = (int) $ p) {if ($ tag = 1) {$ oll [] = $ value;} else if ($ tag = 2) {$ keys = array_keys ($ Oll); $ j = 0; if (is_int ($ key) {while (in_array ($ key, $ keys, true) {$ key ++ ;}} else {while (in_array ($ key, $ keys, true) {$ j ++; $ key. = (string) $ j ;}$ oll [$ key] = $ value ;}else {return false ;}$ key = $ k; $ j = 0; $ keys = array_keys ($ oll); if (is_int ($ key) {$ oll [] = $ v;} else {while (in_array ($ key, $ keys, true) {$ j ++; $ key. = (string) $ j ;}$ oll [$ key] = $ v ;}} else {if ($ I> $ p) {$ key = $ k; $ j = 0; $ keys = array_keys ($ oll); if (is_int ($ key) {$ oll [] = $ v;} else {while (In_array ($ key, $ keys, true) {$ j ++; $ key. = (string) $ j ;}$ oll [$ key] = $ v ;}} else {if (is_int ($ k) {$ oll [] = $ v ;} else {$ oll [$ k] = $ v ;}}$ this-> oll = $ oll; return true ;} /*** return an element in the sequence table based on the element position ** @ param int $ position the element position starts from 1 * @ return array ('value' => ...) element value, array ('key' => ...) element subscript */public function getElemForPos ($ position) {$ I = 0; $ len = count ($ this-> oll); $ position = (int) $ position; if ($ position> $ len | $ position <1) {Return false;} foreach ($ this-> oll as $ val) {$ I ++; if ($ I = $ position) {return array ('value' => current ($ this-> oll), 'key' => key ($ this-> oll ));}}} /*** delete an element in the sequence table based on the subscript or element value ** @ param mixed $ value element subscript or value * @ param int $ tag 1 indicates that $ value is a subscript, 2 indicates that $ value is the element value * @ return bool. true is returned for success, and false is returned for failure. **/public function getDeleteElement ($ value, $ tag = 1) {$ len = count ($ this-> oll); foreach ($ this-> oll as $ k => $ v) {if ($ tag = 1) {if (st Rcmp ($ k, $ value) === 0) {} else {if (is_int ($ k) {$ oll [] = $ v ;} else {$ oll [$ k] = $ v ;}} if ($ tag = 2) {if (strcmp ($ v, $ value) === 0) {} else {if (is_int ($ k) {$ oll [] = $ v;} else {$ oll [$ k] = $ v ;}}}} $ this-> oll = $ oll; if (count ($ this-> oll) ==$ len) {return false;} return true ;} /*** delete an element in the sequence table according to the element position ** @ param int $ position the element position starts from 1 * @ return bool success returns true, returns false if an error occurs. **/public function getDeleteEleForPos ($ position) {$ len = count ($ thi S-> oll); $ I = 0; $ position = (int) $ position; if ($ position> $ len | $ position <1) {return false ;} foreach ($ this-> oll as $ k => $ v) {$ I ++; if ($ I = $ position) {} else {if (is_int ($ k) {$ oll [] = $ v;} else {$ oll [$ k] = $ v ;}}} $ this-> oll = $ oll; if (count ($ this-> oll) ==$ len) {return false;} return true ;}}?> $ Oll = new OrderLinearList (array ('Xu '=> 'Xu dianyang', 32, "right", 'dianyang '=> 10,455 )); // Determine whether the sequence table is empty. if the returned value is false, the var_dump ($ oll-> isEmpty () is not empty. echo"
"; // Return the length of the sequence table. 6 echo $ oll-> getLength (); echo" is returned"
"; // Returns an element var_dump ($ oll-> getElement (1); echo"
"; // Return the location of an element in the sequence table echo $ oll-> getElementPosition (" right "); echo"
"; // Return the direct precursor element var_dump ($ oll-> getElementPredecessorr (" right ", 2) of an element in the sequence table; echo"
"; // Return the directly successor element var_dump ($ oll-> getElementSubsequence (" right ", 2) of an element in the sequence table; echo"
"; // Return an element var_dump ($ oll-> getElemForPos (2) in the sequence table based on the element location; echo"
"; // Delete an element var_dump ($ oll-> getDeleteElement ('Xu dianyang ', $ tag = 2) in the sequence table based on the subscript or element value); echo"
"; // Delete an element var_dump ($ oll-> getDeleteEleForPos (1) in the sequence table based on the element location; echo"
"; $ Oll-> getInsertElement (3," Xu Zhen ", $ key =" xuzheng ", $ tag = 2); var_dump ($ oll-> oll); echo"
";?>