44 lines
2.2 KiB
C++
44 lines
2.2 KiB
C++
#include <string>
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#include "pbEntry.h"
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#pragma once
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typedef int (*hashFunctionPtr)(std::string); // typedefinition of a pointer for a hashfunction; they all need conform to the guideline: int <functionName>(std::string <param>)
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int lastNumber(std::string telNr); // hash algorithm that uses only the last digit of a given telNr
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int firstThreeNumbers(std::string telNr); // hash algorithm that uses the first three digits of a given telNr
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int lastThreeNumbers(std::string telNr); // hash algorithm that uses the last three digits of a given telNr
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int mod17(std::string telNr); // hash algorithm that takes a given telNr mod17
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class HashTable {
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private:
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class HashFunction { // private inner class to make hash functions managable
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public:
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int size;
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std::string name;
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hashFunctionPtr algorithm;
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HashFunction(std::string name, hashFunctionPtr algorithm, int size); // constructor
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};
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HashFunction availableAlgorithms[4] = { {"lastNumber", lastNumber, 10}, {"firstThreeNumbers", firstThreeNumbers, 1000}, {"lastThreeNumbers", lastThreeNumbers, 1000}, {"mod17", mod17, 17}};
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class HashNode { // private inner class for HashNodes that have a key (which will be the telephone number) and a value of type PbEntry
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public:
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std::string key = "";
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PbEntry* phonebookEntry;
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};
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public:
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int size; // m in lecture
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int numberOfEntries; // n in lecture
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HashNode* entries; // nodes of the hash table
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hashFunctionPtr hashFunction; // pointer to the hash algorithm used is stored in a private variable of type hashFunctionPtr - see beginning of this file
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void insert(PbEntry* entry);
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const PbEntry* search(std::string key);
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bool deleteItem(std::string key);
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void print();
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void setHashFunction(std::string name);
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HashTable(); // default constructor
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}; |