docs: update the whole repository

* fix some bugs
* delete duplicate files
* format code

DataStructures/Trees/PrintTopViewofTree.java

@@ -1,87 +1,88 @@
-// Java program to print top view of Binary tree
-import java.util.*;
- 
+package DataStructures.Trees;// Java program to print top view of Binary tree
+
+import java.util.HashSet;
+import java.util.LinkedList;
+import java.util.Queue;
+
 // Class for a tree node
-class TreeNode
-{
+class TreeNode {
     // Members
     int key;
     TreeNode left, right;
- 
+
     // Constructor
-    public TreeNode(int key)
-    {
+    public TreeNode(int key) {
         this.key = key;
         left = right = null;
     }
 }
- 
+
 // A class to represent a queue item. The queue is used to do Level
 // order traversal. Every Queue item contains node and horizontal
 // distance of node from root
-class QItem
-{
-   TreeNode node;
-   int hd;
-   public QItem(TreeNode n, int h)
-   {
+class QItem {
+    TreeNode node;
+    int hd;
+
+    public QItem(TreeNode n, int h) {
         node = n;
         hd = h;
-   }
+    }
 }
- 
+
 // Class for a Binary Tree
-class Tree
-{
+class Tree {
     TreeNode root;
- 
+
     // Constructors
-    public Tree()  { root = null; }
-    public Tree(TreeNode n) { root = n; }
- 
+    public Tree() {
+        root = null;
+    }
+
+    public Tree(TreeNode n) {
+        root = n;
+    }
+
     // This method prints nodes in top view of binary tree
-    public void printTopView()
-    {
+    public void printTopView() {
         // base case
-        if (root == null) {  return;  }
- 
+        if (root == null) {
+            return;
+        }
+
         // Creates an empty hashset
         HashSet<Integer> set = new HashSet<>();
- 
+
         // Create a queue and add root to it
         Queue<QItem> Q = new LinkedList<QItem>();
         Q.add(new QItem(root, 0)); // Horizontal distance of root is 0
- 
+
         // Standard BFS or level order traversal loop
-        while (!Q.isEmpty())
-        {
+        while (!Q.isEmpty()) {
             // Remove the front item and get its details
             QItem qi = Q.remove();
             int hd = qi.hd;
             TreeNode n = qi.node;
- 
+
             // If this is the first node at its horizontal distance,
             // then this node is in top view
-            if (!set.contains(hd))
-            {
+            if (!set.contains(hd)) {
                 set.add(hd);
                 System.out.print(n.key + " ");
             }
- 
+
             // Enqueue left and right children of current node
             if (n.left != null)
-                Q.add(new QItem(n.left, hd-1));
+                Q.add(new QItem(n.left, hd - 1));
             if (n.right != null)
-                Q.add(new QItem(n.right, hd+1));
+                Q.add(new QItem(n.right, hd + 1));
         }
     }
 }
- 
+
 // Driver class to test above methods
-public class PrintTopViewofTree
-{
-    public static void main(String[] args)
-    {
+public class PrintTopViewofTree {
+    public static void main(String[] args) {
         /* Create following Binary Tree
              1
            /  \