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#include <iostream>
#include <ctime>
#include <stdlib.h>
#include <functional>
#include <cmath>
#include <string>
#include <iomanip>
void fillArray(int[], int);
int linearProbeHash(int[], int);
int quadraticProbeHash(int[], int);
unsigned int hash(const std::string);
int main()
{
int arr1[1000];
int arr2[2000];
int arr3[3000];
int arr4[4000];
int arr5[5000];
int arr6[6000];
int arr7[7000];
int arr8[8000];
int arr9[9000];
int arr10[10000];
int linearCollisions[10];
int quadraticCollisions[10];
int doubleCollisions[10];
fillArray(arr1, 1000);
fillArray(arr2, 2000);
fillArray(arr3, 3000);
fillArray(arr4, 4000);
fillArray(arr5, 5000);
fillArray(arr6, 6000);
fillArray(arr7, 7000);
fillArray(arr8, 8000);
fillArray(arr9, 9000);
fillArray(arr10, 10000);
//Gather data for each hash function
linearCollisions[0] = linearProbeHash(arr1, 1000);
linearCollisions[1] = linearProbeHash(arr2, 2000);
linearCollisions[2] = linearProbeHash(arr3, 3000);
linearCollisions[3] = linearProbeHash(arr4, 4000);
linearCollisions[4] = linearProbeHash(arr5, 5000);
linearCollisions[5] = linearProbeHash(arr6, 6000);
linearCollisions[6] = linearProbeHash(arr7, 7000);
linearCollisions[7] = linearProbeHash(arr8, 8000);
linearCollisions[8] = linearProbeHash(arr9, 9000);
linearCollisions[9] = linearProbeHash(arr10, 10000);
quadraticCollisions[0] = quadraticProbeHash(arr1, 1000);
quadraticCollisions[1] = quadraticProbeHash(arr2, 2000);
quadraticCollisions[2] = quadraticProbeHash(arr3, 3000);
quadraticCollisions[3] = quadraticProbeHash(arr4, 4000);
quadraticCollisions[4] = quadraticProbeHash(arr5, 5000);
quadraticCollisions[5] = quadraticProbeHash(arr6, 6000);
quadraticCollisions[6] = quadraticProbeHash(arr7, 7000);
quadraticCollisions[7] = quadraticProbeHash(arr8, 8000);
quadraticCollisions[8] = quadraticProbeHash(arr9, 9000);
quadraticCollisions[9] = quadraticProbeHash(arr10, 10000);
//Display all of the data
std::cout << std::left << std::setw(40) << "Size: ";
for(int i = 0; i < 10; ++i)
std::cout << std::setw(10) << (i + 1) * 1000;
std::cout << std::left << std::setw(41) << "\nLinear: ";
for(int i = 0; i < 10; ++i)
std::cout << std::setw(10) << linearCollisions[i];
std::cout << std::left << std::setw(41) << "\nQuadratic: ";
for(int i = 0; i < 10; ++i)
std::cout << std::setw(10) << quadraticCollisions[i];
return 0;
}
int quadraticProbeHash(int array[], int size)
{
//Initialize every element in the hash table to nullptr
//This makes it easier to tell if a collision has occurred
int *hashTable[10001] = {nullptr};
int collisionCount = 0;
int index;
int start;
for(int i = 0; i < size; ++i)
{
char buffer [33];
//index = intHash(array[i]) %10001;
index = hash(std::string(itoa(array[i], buffer, 10))) % 10001;
if(hashTable[index] == nullptr)
{
hashTable[index] = &array[i];
}
else
{
++collisionCount;
int j = 0;
int position = index;
do
{
if(hashTable[index] == nullptr)
{
hashTable[index] = &array[i];
}
else
{
index = (position + (int)std::pow(j, 2)) % 10001;
}
j++;
}while(hashTable[j] != nullptr);
}
}
return collisionCount;
}
int linearProbeHash(int array[], int size)
{
//Initialize every element in the hash table to nullptr
//This makes it easier to tell if a collision has occurred
int *hashTable[10001] = {nullptr};
int collisionCount = 0;
int index;
for(int i = 0; i < size; ++i)
{
char buffer [33];
index = hash(std::string(itoa(array[i], buffer, 10))) % 10001;
if(hashTable[index] == nullptr)
{
hashTable[index] = &array[i];
}
else
{
++collisionCount;
int j = 0;
do
{
if(hashTable[j] == nullptr)
{
hashTable[j] = &array[i];
}
else
++j;
}while(hashTable[j] != nullptr);
}
}
return collisionCount;
}
//Accepts an array and size of the array and fills the array with random integers.
void fillArray(int array[], int size )
{
srand(time(0));
for(int i = 0; i < size; ++i)
array[i] = rand();
}
//This hash function was found in the book Data Structures and Algorithm Analysis in C++ (Textbook for the class)
unsigned int hash(const std::string key)
{
unsigned int hash = 0;
for(char ch :key)
hash = 37 * hash + ch;
return hash;
}
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