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Hashing.java
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Hashing.java
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import java.util.LinkedHashSet;
import java.util.Random;
import java.util.Set;
import org.knowm.xchart.QuickChart;
import org.knowm.xchart.SwingWrapper;
import org.knowm.xchart.XYChart;
public class Hashing {
static int size=100;
public static void main(String[] args) {
Random rand=new Random();
LinearTable table=new LinearTable(size);
int value;
double loadFactor[]=new double[size];
double collisions1[]=new double[size];
double collisions2[]=new double[size];
double collisions3[]=new double[size];
for(int i=0;i<size;i++){
loadFactor[i]=(i+1)/100D;
}
Set<Integer> generated=new LinkedHashSet<>();
while(generated.size()<size){
value=rand.nextInt(size);
generated.add(value);
}
int i=0;
for(Integer val:generated){
System.out.print(val+ " ");
if(i>0){
collisions1[i]=collisions1[i-1]+table.insert(val);
collisions2[i]=collisions2[i-1]+table.insertQuadratic(val);
collisions3[i]=collisions3[i-1]+table.insertDoubleHashing(val);
}else{
collisions1[0]=table.insert(val);
collisions2[i]=table.insertQuadratic(val);
collisions3[i]=table.insertDoubleHashing(val);
}
i++;
}
table.printHashtable();
//printComparison(loadFactor,collisions1);
XYChart chart=QuickChart.getChart("Linear Probing","X","Y","y(x)",loadFactor,collisions1);
new SwingWrapper(chart).displayChart();
XYChart chart2=QuickChart.getChart("Quadratic Probing","X","Y","y(x)",loadFactor,collisions2);
new SwingWrapper(chart2).displayChart();
XYChart chart3=QuickChart.getChart("Double Hashing","X","Y","y(x)",loadFactor,collisions3);
new SwingWrapper(chart3).displayChart();
}
private static void printComparison(double l[],double c[]){
System.out.println("\nLoad Factor\t\tNo.of Collisions");
System.out.println("====================================");
for(int i=0;i<size;i++){
System.out.println(l[i]+" "+c[i]);
}
}
}
class LinearTable{
private int size;
private int keys[];
private int values[];
public LinearTable(int size){
this.size=size;
keys=new int[size];
values=new int[size];
for(int i=0;i<size;i++){
keys[i]=i;
values[i]=0;
}
}
public int getSize() //function to get size of hash table
{
return size;
}
public boolean isFull() //Function to check if hash table is full
{
return size == 100;
}
public boolean isEmpty() //Function to check if hash table is empty
{
return getSize() == 0;
}
public int get(){//function to get key
return 0;
}
private int hash(int val){
return val % 15;
}
private int hash2(int val){
return val% 21;
}
public int insert(int val){
int index= hash(val);
int num_of_collisions=0;
int i=index;
do{
if(values[i]==0){
values[i]=val;
if(i==index)
return 0;
else
return num_of_collisions;
}
i=(i+1)%size;
num_of_collisions++;
}while(i!=index);
return num_of_collisions;
}
public int insertQuadratic(int val){
int index=hash(val);
int num_of_collisions=0;
int i=index,t=1;
do{
if(values[i]==0){
values[i]=val;
if(i==index)
return 0;
else
return num_of_collisions;
}
i=(i+(t*t))%size;
t++;
num_of_collisions++;
}while(i!=index);
return num_of_collisions;
}
public int insertDoubleHashing(int val){
int index=hash(val);
int num_of_collisions=0;
int i=index,t=1;
do{
if(values[i]==0){
values[i]=val;
if(i==index)
return 0;
else
return num_of_collisions;
}
i=(i+(t*hash2(val)))%size;
t++;
num_of_collisions++;
}while(i!=index);
return num_of_collisions;
}
public void printHashtable(){
System.out.println("Hash Table:");
for(int i=0;i<size;i++){
System.out.println(keys[i]+" "+ values[i]);
}
}
}