made my own hashmap

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

@@ -1,19 +1,101 @@
 package core.basesyntax;
 
 public class MyHashMap<K, V> implements MyMap<K, V> {
+    private static final int INIT_CAP = 16;
+    private static final double MAX_SIZE = 0.75;
+    private int capacity;
+    private int size;
+    private double threshold;
+    private Node<K, V>[] table;
+
+    public MyHashMap() {
+        table = new Node[INIT_CAP];
+        capacity = INIT_CAP;
+        threshold = INIT_CAP * MAX_SIZE;
+    }
 
     @Override
     public void put(K key, V value) {
+        if (size >= threshold) {
+            resize();
+        }
+        int index = hash(key);
+        Node<K, V> node = table[index];
+
+        if (node == null) {
+            table[index] = new Node<>(key, value, null);
+            size++;
+            return;
+        }
 
+        while (node != null) {
+            if ((key == node.key) || (key != null && key.equals(node.key))) {
+                node.value = value;
+                return;
+            }
+            if (node.next == null) {
+                node.next = new Node<>(key, value, null);
+                size++;
+                return;
+            }
+            node = node.next;
+
+        }
     }
 
     @Override
     public V getValue(K key) {
+        int index = hash(key);
+        Node<K, V> node = table[index];
+        while (node != null) {
+            if ((key == node.key) || (key != null && key.equals(node.key))) {
+                return node.value;
+            }
+            node = node.next;
+        }
         return null;
     }
 
     @Override
     public int getSize() {
-        return 0;
+        return size;
+    }
+
+    private void resize() {
+        size = 0;
+        int oldCapacity = capacity;
+        capacity += capacity;
+        Node<K, V>[] oldTable = table;
+        Node<K, V>[] newTable = new Node[capacity];
+        table = newTable;
+        for (int i = 0; i < oldCapacity; i++) {
+            Node<K, V> node = oldTable[i];
+
+            while (node != null) {
+                Node<K, V> next = node.next;
+                put(node.key, node.value);
+                node = next;
+            }
+        }
+        threshold = capacity * MAX_SIZE;
+    }
+
+    private int hash(Object key) {
+        if (key == null) {
+            return 0;
+        }
+        return Math.abs(key.hashCode() % capacity);
+    }
+
+    class Node<K, V> {
+        private K key;
+        private V value;
+        private Node<K, V> next;
+
+        public Node(K key, V value, Node<K, V> next) {
+            this.key = key;
+            this.value = value;
+            this.next = next;
+        }
     }
 }