mirror of
https://gitlab.com/freepascal.org/fpc/source.git
synced 2025-06-27 10:08:31 +02:00
103 lines
4.8 KiB
TeX
103 lines
4.8 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}
|
|
|
|
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!function InsertAndGetIterator! & $O(\lg N)$\\
|
|
\verb!(key:TKey; value: TValue):TIterator! & \\ \hline
|
|
\multicolumn{2}{|m{15cm}|}{Same as Insert but also returns iterator poiting to inserted element.} \\\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):TIterator! & O(lg N) \\\hline
|
|
\multicolumn{2}{|m{15cm}|}{Searches for key in map. If value is not there returns nil. Otherwise
|
|
returns iterator, which can be used for retrieving data from map.} \\\hline\hline
|
|
|
|
\verb!function FindLess(key: T):TIterator! & 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 iterator, which can be used for retrieving data from map.} \\\hline\hline
|
|
|
|
\verb!function FindLessEqual(key: T):TIterator! & 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 iterator, which can be used for retrieving data from map.} \\\hline\hline
|
|
|
|
\verb!function FindGreater(key: T):TIterator! & 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 iterator, which can be used for retrieving data from map.} \\\hline\hline
|
|
|
|
\verb!function FindGreaterEqual(key: T):TIterator! & 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 iterator, which can be used for retrieving data from map.} \\\hline\hline
|
|
|
|
\verb!function Min:TIterator! & O(lg N) \\\hline
|
|
\multicolumn{2}{|m{15cm}|}{Returns iterator pointing to smallest key of map. If map is empty returns
|
|
nil.} \\\hline\hline
|
|
|
|
\verb!function Max:TIterator! & O(lg N) \\\hline
|
|
\multicolumn{2}{|m{15cm}|}{Returns iterator pointing to largest key of map. If map is empty returns
|
|
nil.} \\\hline\hline
|
|
|
|
\verb!function IsEmpty(): boolean! & O(1) \\ \hline
|
|
\multicolumn{2}{|m{15cm}|}{Returns true when map is empty.} \\\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}
|
|
|
|
Some methods return type TIterator, which has following methods:
|
|
\begin{longtable}{|m{10cm}|m{5cm}|}
|
|
\hline
|
|
Method & Complexity guarantees \\ \hline
|
|
\multicolumn{2}{|m{15cm}|}{Description} \\ \hline\hline
|
|
\verb!function Next:boolean! & O(lg N) worst case, but traversal from smallest element to
|
|
largest takes O(N) time \\\hline
|
|
\multicolumn{2}{|m{15cm}|}{Moves iterator to element with smallest larger key. Returns true on
|
|
success. If the iterator is already pointing on element with largest key returns false.} \\\hline\hline
|
|
|
|
\verb!function Prev:boolean! & O(lg N) worst case, but traversal from largest element to
|
|
smallest takes O(N) time \\\hline
|
|
\multicolumn{2}{|m{15cm}|}{Moves iterator to element with largest smaller key. Returns true on
|
|
success. If the iterator is already pointing on element with smallest key returns false.} \\\hline\hline
|
|
|
|
\verb!property Key:TKey! & $O(1)$ \\\hline
|
|
\multicolumn{2}{|m{15cm}|}{Property, which allows reading the key.} \\\hline
|
|
|
|
\verb!property Value:TValue! & $O(1)$ \\\hline
|
|
\multicolumn{2}{|m{15cm}|}{Property, which allows reading and writing of the value.} \\\hline
|
|
\verb!property MutableValue:PValue! & $O(1)$ \\\hline
|
|
\multicolumn{2}{|m{15cm}|}{Returns pointer on stored value. Usefull for accessing records and
|
|
objects.} \\\hline
|
|
|
|
|
|
\end{longtable}
|