docs: update the whole repository

* fix some bugs
* delete duplicate files
* format code

DataStructures/Trees/AVLTree.java

@@ -1,19 +1,21 @@
+package DataStructures.Trees;
+
 public class AVLTree {
- 
+
     private Node root;
- 
+
     private class Node {
         private int key;
         private int balance;
         private int height;
         private Node left, right, parent;
- 
+
         Node(int k, Node p) {
             key = k;
             parent = p;
         }
     }
- 
+
     public boolean insert(int key) {
         if (root == null)
             root = new Node(key, null);
@@ -23,12 +25,12 @@ public class AVLTree {
             while (true) {
                 if (n.key == key)
                     return false;
- 
+
                 parent = n;
- 
+
                 boolean goLeft = n.key > key;
                 n = goLeft ? n.left : n.right;
- 
+
                 if (n == null) {
                     if (goLeft) {
                         parent.left = new Node(key, parent);
@@ -42,38 +44,38 @@ public class AVLTree {
         }
         return true;
     }
- 
-    private void delete(Node node){
-        if(node.left == null && node.right == null){
-            if(node.parent == null) root = null;
-            else{
+
+    private void delete(Node node) {
+        if (node.left == null && node.right == null) {
+            if (node.parent == null) root = null;
+            else {
                 Node parent = node.parent;
-                if(parent.left == node){
+                if (parent.left == node) {
                     parent.left = null;
-                }else parent.right = null;
+                } else parent.right = null;
                 rebalance(parent);
             }
             return;
         }
-        if(node.left!=null){
+        if (node.left != null) {
             Node child = node.left;
-            while (child.right!=null) child = child.right;
+            while (child.right != null) child = child.right;
             node.key = child.key;
             delete(child);
-        }else{
+        } else {
             Node child = node.right;
-            while (child.left!=null) child = child.left;
+            while (child.left != null) child = child.left;
             node.key = child.key;
             delete(child);
         }
     }
- 
+
     public void delete(int delKey) {
         if (root == null)
             return;
         Node node = root;
         Node child = root;
- 
+
         while (child != null) {
             node = child;
             child = delKey >= node.key ? node.right : node.left;
@@ -83,43 +85,43 @@ public class AVLTree {
             }
         }
     }
- 
+
     private void rebalance(Node n) {
         setBalance(n);
- 
+
         if (n.balance == -2) {
             if (height(n.left.left) >= height(n.left.right))
                 n = rotateRight(n);
             else
                 n = rotateLeftThenRight(n);
- 
+
         } else if (n.balance == 2) {
             if (height(n.right.right) >= height(n.right.left))
                 n = rotateLeft(n);
             else
                 n = rotateRightThenLeft(n);
         }
- 
+
         if (n.parent != null) {
             rebalance(n.parent);
         } else {
             root = n;
         }
     }
- 
+
     private Node rotateLeft(Node a) {
- 
+
         Node b = a.right;
         b.parent = a.parent;
- 
+
         a.right = b.left;
- 
+
         if (a.right != null)
             a.right.parent = a;
- 
+
         b.left = a;
         a.parent = b;
- 
+
         if (b.parent != null) {
             if (b.parent.right == a) {
                 b.parent.right = b;
@@ -127,25 +129,25 @@ public class AVLTree {
                 b.parent.left = b;
             }
         }
- 
+
         setBalance(a, b);
- 
+
         return b;
     }
- 
+
     private Node rotateRight(Node a) {
- 
+
         Node b = a.left;
         b.parent = a.parent;
- 
+
         a.left = b.right;
- 
+
         if (a.left != null)
             a.left.parent = a;
- 
+
         b.right = a;
         a.parent = b;
- 
+
         if (b.parent != null) {
             if (b.parent.right == a) {
                 b.parent.right = b;
@@ -153,39 +155,39 @@ public class AVLTree {
                 b.parent.left = b;
             }
         }
- 
+
         setBalance(a, b);
- 
+
         return b;
     }
- 
+
     private Node rotateLeftThenRight(Node n) {
         n.left = rotateLeft(n.left);
         return rotateRight(n);
     }
- 
+
     private Node rotateRightThenLeft(Node n) {
         n.right = rotateRight(n.right);
         return rotateLeft(n);
     }
- 
+
     private int height(Node n) {
         if (n == null)
             return -1;
         return n.height;
     }
- 
+
     private void setBalance(Node... nodes) {
         for (Node n : nodes) {
             reheight(n);
             n.balance = height(n.right) - height(n.left);
         }
     }
- 
+
     public void printBalance() {
         printBalance(root);
     }
- 
+
     private void printBalance(Node n) {
         if (n != null) {
             printBalance(n.left);
@@ -193,20 +195,20 @@ public class AVLTree {
             printBalance(n.right);
         }
     }
- 
-    private void reheight(Node node){
-        if(node!=null){
-            node.height=1 + Math.max(height(node.left), height(node.right));
+
+    private void reheight(Node node) {
+        if (node != null) {
+            node.height = 1 + Math.max(height(node.left), height(node.right));
         }
     }
- 
+
     public static void main(String[] args) {
         AVLTree tree = new AVLTree();
- 
+
         System.out.println("Inserting values 1 to 10");
         for (int i = 1; i < 10; i++)
             tree.insert(i);
- 
+
         System.out.print("Printing balance: ");
         tree.printBalance();
     }