ready for check

src/main/java/core/basesyntax/MyHashMap.java

@@ -1,19 +1,106 @@
 package core.basesyntax;
 
 public class MyHashMap<K, V> implements MyMap<K, V> {
+    private static final int DEFAULT_CAPACITY = 16;
+    private static final double LOAD_FACTOR = 0.75;
+
+    @SuppressWarnings("unchecked")
+    private Node<K, V>[] table;
+    private int size;
+    private int threshold;
+
+    public MyHashMap() {
+        table = new Node[DEFAULT_CAPACITY];
+        threshold = (int) (DEFAULT_CAPACITY * LOAD_FACTOR);
+    }
+
+    private int getHash(K key) {
+        return (key == null) ? 0 : Math.abs(key.hashCode());
+    }
+
+    private int getIndex(int hash, int length) {
+        return hash % length;
+    }
 
     @Override
     public void put(K key, V value) {
+        if (size >= threshold) {
+            resize();
+        }
+        int hash = getHash(key);
+        int index = getIndex(hash, table.length);
+        if (table[index] == null) {
+            table[index] = new Node<>(hash, key, value, null);
+            size++;
+            return;
+        }
+        Node<K, V> currentNode = table[index];
+        while (currentNode != null) {
+            if (checkEquals(currentNode.key, key)) {
+                currentNode.value = value;
+                return;
+            }
+            if (currentNode.next == null) {
+                break;
+            }
+            currentNode = currentNode.next;
+        }
+        currentNode.next = new Node<>(hash, key, value, null);
+        size++;
+    }
+
+    private void resize() {
+        Node<K, V>[] oldTable = table;
+        int newCapacity = oldTable.length << 1;
+        table = new Node[newCapacity];
+        threshold = (int) (newCapacity * LOAD_FACTOR);
+        size = 0;
+        for (Node<K, V> node : oldTable) {
+            Node<K, V> currentNode = node;
+            while (currentNode != null) {
+                put(currentNode.key, currentNode.value);
+                currentNode = currentNode.next;
+            }
+        }
+    }
 
+    private boolean checkEquals(K keyInMap, K keyToFind) {
+        if (keyInMap == keyToFind) {
+            return true;
+        }
+        return keyInMap != null && keyInMap.equals(keyToFind);
     }
 
     @Override
     public V getValue(K key) {
+        int hash = getHash(key);
+        int index = getIndex(hash, table.length);
+        Node<K,V> currentNode = table[index];
+        while (currentNode != null) {
+            if (checkEquals(currentNode.key, key)) {
+                return currentNode.value;
+            }
+            currentNode = currentNode.next;
+        }
         return null;
     }
 
     @Override
     public int getSize() {
-        return 0;
+        return size;
+    }
+
+    private static class Node<K, V> {
+        private final int hash;
+        private final K key;
+        private V value;
+        private Node<K, V> next;
+
+        public Node(int hash, K key, V value, Node<K, V> next) {
+            this.hash = hash;
+            this.key = key;
+            this.value = value;
+            this.next = next;
+        }
     }
 }