8000 hashmap 2 · anmolpant/Coding-Ninjas-Java@17188f2 · GitHub
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hashmap 2
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‎Data Structures in Java/Level 3/Hashmaps/HashMap Implementation-2/Map.java

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import java.util.ArrayList;
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public class Map <K, V> {
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ArrayList<MapNode<K, V>> buckets;
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int size;
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int numBuckets;
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public Map() {
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numBuckets = 5;
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buckets = new ArrayList<>();
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for (int i = 0; i < numBuckets; i++) {
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buckets.add(null);
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}
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}
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private int getBucketIndex(K key) {
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int hashCode = key.hashCode();
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return hashCode % numBuckets;
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}
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public int size() {
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return size;
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}
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public V removeKey(K key) {
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int bucketIndex = getBucketIndex(key);
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MapNode<K, V> head = buckets.get(bucketIndex);
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MapNode<K, V> prev = null;
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while (head != null) {
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if (head.key.equals(key)) {
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size--;
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if (prev == null) {
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buckets.set(bucketIndex, head.next);
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} else {
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prev.next = head.next;
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}
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return head.value;
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}
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prev = head;
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head = head.next;
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}
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return null;
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}
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public V getValue(K key) {
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int bucketIndex = getBucketIndex(key);
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MapNode<K, V> head = buckets.get(bucketIndex);
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while (head != null) {
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if (head.key.equals(key)) {
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return head.value;
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}
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head = head.next;
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}
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return null;
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}
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public void insert(K key, V value) {
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int bucketIndex = getBucketIndex(key);
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MapNode<K, V> head = buckets.get(bucketIndex);
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while (head != null) {
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if (head.key.equals(key)) {
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head.value = value;
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return;
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}
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head = head.next;
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}
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head = buckets.get(bucketIndex);
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MapNode<K, V> newElementNode = new MapNode<K, V>(key , value);
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size++;
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newElementNode.next = head;
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buckets.set(bucketIndex, newElementNode);
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}
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}

‎Data Structures in Java/Level 3/Hashmaps/HashMap Implementation-2/MapNode.java

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public class MapNode<K, V> {
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K key;
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V value;
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MapNode<K, V> next;
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public MapNode(K key, V value) {
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this.key = key;
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this.value = value;
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}
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}

‎Data Structures in Java/Level 3/Hashmaps/HashMap Implementation-2/__MACOSX/._Map.java

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