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SCHashTable.java
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216 lines (183 loc) · 5.58 KB
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package HashTable.SeparateChaining;
import HashTable.HashTableInterface;
import java.io.File;
import java.util.function.Function;
public class SCHashTable<K, V> implements HashTableInterface<K, V> {
private Node[] array;
private Function<K, Integer> foh;
private int tableSize = INITIAL_TABLE_SIZE;
private int size = 0;
private int numCollisions = 0;
private int numResizes = 0;
public SCHashTable() {
array = new Node[tableSize];
foh = getHashingFunction();
}
public SCHashTable(HASH_FUNCTION type) {
array = new Node[tableSize];
foh = getHashingFunction(type);
}
@Override
public int indexOf(K key) {
return foh.apply(key);
}
@Override
public boolean contains(K key) {
return array[indexOf(key)] != null;
}
@Override
public void put(K key, V val) {
int index = indexOf(key);
if (loadFactor() > LOAD_FACTOR && getTableSize() * 2 < MAX_TABLE_SIZE) {
resize();
}
Node<K, V> node = array[index];
while (node != null) {
if (node.getKey().equals(key)) {
node.setValue(val);
return;
}
node = node.getNext();
}
if (array[index] != null) {
numCollisions++;
}
array[index] = new Node(key, val, array[index]);
size++;
}
@Override
public V get(K key) {
int index = indexOf(key);
Node<K, V> node = array[index];
while (node != null) {
if (node.getKey().equals(key)) {
return node.getValue();
}
node = node.getNext();
}
return null;
}
@Override
public void delete(K key) {
int index = indexOf(key);
if (array[index].getKey().equals(key)) {
array[index] = null;
} else {
delete(key, array[index], array[index].getNext());
}
size--;
}
public void delete(K key, Node p, Node node) {
if (node == null) {
return;
}
if (node.getKey().equals(key)) {
p.setNext(node.getNext());
}
delete(key, node, node.getNext());
}
@Override
public void clear() {
array = new Node[tableSize];
size = 0;
numCollisions = 0;
}
@Override
public void resize() {
Node[] oldArray = array;
tableSize = tableSize * 2;
numResizes++;
clear();
for (Node<K, V> node : oldArray) {
while (node != null) {
put(node.getKey(), node.getValue());
node = node.getNext();
}
}
}
@Override
public int getSize() {
return size;
}
@Override
public int getTableSize() {
return tableSize;
}
@Override
public int getNumCollisions() {
return numCollisions;
}
@Override
public int getNumResizes() {
return numResizes;
}
@Override
public void print() {
for (int i = 0; i < array.length; i++) {
System.out.print(i + " -> ");
if (array[i] != null) {
Node node = array[i];
while (node != null) {
System.out.print(" " + node);
node = node.getNext();
}
}
System.out.println();
}
}
@Override
public void printGraph() {
System.out.println("----------- Print Graph-----------");
for (int i = 0; i < array.length; i++) {
System.out.print(i + " | ");
if (array[i] != null) {
Node node = array[i];
while (node != null) {
System.out.print(BLACK_CIRCLE);
node = node.getNext();
}
}
System.out.println();
}
}
@Override
public double getDistribution() {
int[] tab = new int[getTableSize()];
for (int i = 0; i < getTableSize(); i++) {
Node node = array[i];
while (node != null) {
tab[i]++;
node = node.getNext();
}
}
return HashTableInterface.getStdDeviation(tab);
}
private static void testing(HASH_FUNCTION type) {
System.out.println("------------------ " + type + " ------------------");
SCHashTable<String, String> table = new SCHashTable<>(type);
for (int i = 0; i < 100000; i++) {
table.put(HashTableInterface.randomString(), HashTableInterface.randomString());
if(i==100 || i==500 || i==1000 || i==2000 || i==5000 || i==10000 || i==50000 || i== 80000 || i==100000)
table.printStatus();
}
}
private static void testing(HASH_FUNCTION type, File file) {
System.out.println("------------------ " + type + " ------------------");
SCHashTable<String, String> ht = new SCHashTable<>(type);
HashTableInterface.importFromFile(file, ht);
ht.printStatus();
}
public static void main(String[] args) {
// testing using values from a file
File file = new File("src/HashTable/data.txt");
testing(HASH_FUNCTION.UNIVERSAL, file);
testing(HASH_FUNCTION.MULTIPLICATIF, file);
testing(HASH_FUNCTION.MODULO, file);
// testing using random values
/*
testing(HASH_FUNCTION.UNIVERSAL);
testing(HASH_FUNCTION.MULTIPLICATIF);
testing(HASH_FUNCTION.MODULO);
*/
}
}