\chapter{THashMap} Implements container for unordered 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 is a hash functor (class which has class function hash, which takes element and number $n$ and returns hash of the element in range $0, 1, \dots, n-1$). Usage example: \lstinputlisting[language=Pascal]{hashmapexample.pp} Memory complexity: Arounds two times of size of stored elements 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(1) \\ \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 Contains(key: TKey):boolean! & O(1) on average \\\hline \multicolumn{2}{|m{15cm}|}{Checks whether element with given key is in map.} \\\hline\hline \verb!function Iterator:TIterator! & O(1) on average \\\hline \multicolumn{2}{|m{15cm}|}{Returns iterator allowing traversal through 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(1) on average \\\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(N) worst case, but traversal of whole set takes O(N) time \\\hline \multicolumn{2}{|m{15cm}|}{Moves iterator to next larger element in set. Returns true on success. If the iterator is already pointing on last element 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}