added BinaryTree impl program in Java

17_Tree/BinaryTree.java

@@ -0,0 +1,84 @@
+import java.util.LinkedList;  
+import java.util.Queue;  
+
+public class BinaryTree {  
+
+      //Represent the node of binary tree  
+      public static class Node{  
+        int data;  
+        Node left;  
+        Node right;  
+
+        public Node(int data){  
+          //Assign data to the new node, set left and right children to null  
+          this.data = data;  
+          this.left = null;  
+          this.right = null;  
+        }  
+      }  
+
+      //Represent the root of binary tree  
+      public Node root;  
+
+      public BinaryTree(){  
+        root = null;  
+      }  
+
+      //findMaximumWidth() will find out the maximum width of the given binary tree  
+      public int findMaximumWidth() {  
+          int maxWidth = 0;  
+
+          //Variable nodesInLevel keep tracks of number of nodes in each level  
+          int nodesInLevel = 0;  
+          //queue will be used to keep track of nodes of tree level-wise  
+          Queue<Node> queue = new LinkedList<Node>();  
+
+          //Check if root is null, then width will be 0  
+          if(root == null) {  
+              System.out.println("Tree is empty");  
+              return 0;  
+          }  
+          else {  
+              //Add root node to queue as it represents the first level  
+              queue.add(root);  
+
+              while(queue.size() != 0) {  
+
+                  //Variable nodesInLevel will hold the size of queue i.e. number of elements in queue  
+                  nodesInLevel = queue.size();  
+                  //maxWidth will hold maximum width.  
+                  //If nodesInLevel is greater than maxWidth then, maxWidth will hold the value of nodesInLevel  
+                  maxWidth = Math.max(maxWidth, nodesInLevel);  
+
+                  //If variable nodesInLevel contains more than one node  
+                  //then, for each node, we'll add left and right child of the node to the queue  
+                  while(nodesInLevel > 0) {  
+                     Node current = queue.remove();  
+                     if(current.left != null)  
+                         queue.add(current.left);  
+                     if(current.right != null)  
+                         queue.add(current.right);  
+                     nodesInLevel--;  
+                  }  
+              }  
+          }  
+          return maxWidth;  
+      }  
+
+      public static void main(String[] args) {  
+
+          BinaryTree bt = new BinaryTree();  
+          //Add nodes to the binary tree  
+          bt.root = new Node(1);  
+          bt.root.left = new Node(2);  
+          bt.root.right = new Node(3);  
+          bt.root.left.left = new Node(4);  
+          bt.root.left.right = new Node(5);  
+          bt.root.right.left = new Node(6);  
+          bt.root.right.right = new Node(7);  
+          bt.root.left.left.left = new Node(8);  
+
+          //Display the maximum width of given tree  
+          System.out.println("Maximum width of the binary tree: " + bt.findMaximumWidth());  
+      }  
+}