mirror of
https://gitlab.com/freepascal.org/fpc/source.git
synced 2025-10-18 06:01:41 +02:00
88 lines
4.3 KiB
TeX
88 lines
4.3 KiB
TeX
\chapter{TMap}
|
|
|
|
Implements container for ordered associative array with unique keys.
|
|
Takes 3 arguments for specialization, first one is type of keys, second one is type of values, third
|
|
one is comparator class for keys.
|
|
Usage example:
|
|
|
|
\lstinputlisting[language=Pascal]{mapexample.pp}
|
|
|
|
Some methods return type TMSet.PNode. Usefull fields are Data.Key, Data.Value, for retrieving
|
|
actual Key and Value from node. This node can be also used for navigation between elements by methods of set class.
|
|
You can also change value in node (but not key).
|
|
(But don't do anything else with it, you can lose data integrity.)
|
|
|
|
Memory complexity:
|
|
Size of stored base + constant overhead for each stored element (3 pointers + one boolean).
|
|
|
|
Members list:
|
|
|
|
\begin{longtable}{|m{10cm}|m{5cm}|}
|
|
\hline
|
|
Method & Complexity guarantees \\ \hline
|
|
\multicolumn{2}{|m{15cm}|}{Description} \\ \hline\hline
|
|
|
|
\verb!Create! & O(1) \\ \hline
|
|
\multicolumn{2}{|m{15cm}|}{Constructor. Creates empty map.} \\ \hline\hline
|
|
|
|
\verb!function Size(): SizeUInt! & O(1) \\ \hline
|
|
\multicolumn{2}{|m{15cm}|}{Returns number of elements in map.} \\\hline\hline
|
|
|
|
\verb!procedure Insert(key: TKey; value: TValue)! &
|
|
O(lg N), N is number of elements in map \\ \hline
|
|
\multicolumn{2}{|m{15cm}|}{Inserts key value pair into map. If key was already there, it will have
|
|
new value assigned.} \\\hline\hline
|
|
|
|
\verb!procedure Delete(key: TKey)! &
|
|
O(lg N) \\ \hline
|
|
\multicolumn{2}{|m{15cm}|}{Deletes key (and associated value) from map. If element is not in map, nothing happens.} \\\hline\hline
|
|
|
|
\verb!function Find(key: T):TMSet.PNode! & O(lg N) \\\hline
|
|
\multicolumn{2}{|m{15cm}|}{Searches for key in map. If value is not there returns nil. Otherwise
|
|
returns pointer to tree node (type TMSet.PNode), which can be used for retrieving data from map.} \\\hline\hline
|
|
|
|
\verb!function FindLess(key: T):TMSet.PNode! & O(lg N) \\\hline
|
|
\multicolumn{2}{|m{15cm}|}{Searches for greatest element less than key in map. If such element is not there returns nil. Otherwise
|
|
returns pointer to tree node (type TMSet.PNode), which can be used for retrieving data from map.} \\\hline\hline
|
|
|
|
\verb!function FindLessEqual(key: T):TMSet.PNode! & O(lg N) \\\hline
|
|
\multicolumn{2}{|m{15cm}|}{Searches for greatest element less or equal than key in map. If such element is not there returns nil. Otherwise
|
|
returns pointer to tree node (type TMSet.PNode), which can be used for retrieving data from map.} \\\hline\hline
|
|
|
|
\verb!function FindGreater(key: T):TMSet.PNode! & O(lg N) \\\hline
|
|
\multicolumn{2}{|m{15cm}|}{Searches for smallest element greater than key in map. If such element is not there returns nil. Otherwise
|
|
returns pointer to tree node (type TMSet.PNode), which can be used for retrieving data from map.} \\\hline\hline
|
|
|
|
\verb!function FindGreaterEqual(key: T):TMSet.PNode! & O(lg N) \\\hline
|
|
\multicolumn{2}{|m{15cm}|}{Searches for smallest element greater or equal than key in map. If such element is not there returns nil. Otherwise
|
|
returns pointer to tree node (type TMSet.PNode), which can be used for retrieving data from map.} \\\hline\hline
|
|
|
|
\verb!function Min:TMSet.PNode! & O(lg N) \\\hline
|
|
\multicolumn{2}{|m{15cm}|}{Returns node containing smallest key of map. If map is empty returns
|
|
nil.} \\\hline\hline
|
|
|
|
\verb!function Max:TMSet.PNode! & O(lg N) \\\hline
|
|
\multicolumn{2}{|m{15cm}|}{Returns node containing largest key of map. If map is empty returns
|
|
nil.} \\\hline\hline
|
|
|
|
\verb!function Next(x:TMSet.PNode):TMSet.PNode! & O(lg N) worst case, but traversal from smallest element to
|
|
largest takes O(N) time \\\hline
|
|
\multicolumn{2}{|m{15cm}|}{Returns successor of x. If x is largest key of map, returns nil.} \\\hline\hline
|
|
|
|
\verb!function Prev(x:TMSet.PNode):TMSet.PNode! & O(lg N) worst case, but traversal from largest element to
|
|
smallest takes O(N) time \\\hline
|
|
\multicolumn{2}{|m{15cm}|}{Returns predecessor of x. If x is smallest key of map, returns nil.} \\\hline\hline
|
|
|
|
\verb!function IsEmpty(): boolean! & O(1) \\ \hline
|
|
\multicolumn{2}{|m{15cm}|}{Returns true when map is empty.} \\\hline
|
|
|
|
\verb!function GetValue(key:TKey):TValue! & O(lg N) \\\hline
|
|
\multicolumn{2}{|m{15cm}|}{Returns value associated with key. Is key isn't in map crashes.} \\\hline
|
|
|
|
\verb!property item[i: Key]: TValue; default;! & O(ln N) \\\hline
|
|
\multicolumn{2}{|m{15cm}|}{Property for accessing key i in map. Can be used just by square
|
|
brackets (its default property).} \\\hline\hline
|
|
|
|
|
|
\end{longtable}
|