hashTable.cpp

#include <iostream>

using namespace std;

const int TABLE_SIZE = 128;

class HashEntry
{
public:
    int key;
    int val;
    HashEntry(int key, int val)
    {
        this->key = key;
        this->val = val;
    }
};

class HashMap
{
private:
    HashEntry **table;
public:
    HashMap()
    {
        table = new HashEntry * [TABLE_SIZE];
        for ( int i = 0 ; i < TABLE_SIZE ; i ++ ){
            table[i] = NULL;
        }
    }
    int HashFunc(int key){
        return key % TABLE_SIZE;
    }
    void insert(int key, int val){
        int hash = HashFunc(key);
        while ( table[hash] != NULL && table[hash]->key != key ){
            hash = HashFunc(hash + 1);
        }
        if ( table[hash] != NULL ){
            delete table[hash];
        }
        table[hash] = new HashEntry(key, val);
    }
    int Search(int key){
        int hash = HashFunc(key);
        while( table[hash] != NULL && table[hash]->key != key ){
            hash = HashFunc(hash + 1);
        }
        if ( table[hash] == NULL ){
            return -1;
        }
        return table[hash]->val;
    }
    void Remove(int key){
        int hash = HashFunc(key);
        while ( table[hash] != NULL ){
            if ( table[hash]->key == key ){
                break;
            }
            hash = HashFunc(hash + 1);
        }
        if ( table[hash] == NULL ){
            cout << "No element found at the key " << key << endl;
            return;
        }
        delete table[hash];
        cout << "Element deleted" << endl;
    }
    ~HashMap()
    {
        for (int i = 0 ; i < TABLE_SIZE ; i ++ ){
            if ( table[i] != NULL ){
                delete table[i];
            }
        }
        delete[] table;
    }
};