Adding InvertBinaryTree

Author: Sahilkumar19

InvertTheBinaryTree.java

@@ -0,0 +1,58 @@
+/*
+Given the root of a binary tree, invert the tree, and return its root.
+
+Example 1:
+Input: root = [4,2,7,1,3,6,9]
+Output: [4,7,2,9,6,3,1]
+ */
+
+import java.util.ArrayList;
+import java.util.LinkedList;
+import java.util.List;
+import java.util.Queue;
+
+public class InvertTheBinaryTree {
+    public static void main(String[] args) {
+        TreeNode root=new TreeNode(4);
+        root.left=new TreeNode(2);
+        root.right=new TreeNode(7);
+        root.left.left=new TreeNode(1);
+        root.left.right=new TreeNode(3);
+        root.right.left=new TreeNode(6);
+        root.right.right=new TreeNode(9);
+        List<Integer> ans=invertTree(root);
+        System.out.println(ans);
+    }
+    public static List<Integer> invertTree(TreeNode root) {
+        List<Integer> result=new ArrayList<>();
+        if (root==null){
+            return result;
+        }
+        Queue<TreeNode> queue=new LinkedList<>();
+        queue.offer(root);
+        result.add(root.data);
+        while (!queue.isEmpty()){
+            int levesize= queue.size();
+            for (int i = 0; i < levesize; i++) {
+                TreeNode currentnode=queue.poll();
+                if (currentnode.right!=null){
+                    queue.offer(currentnode.right);
+                    result.add(currentnode.right.data);
+                }
+                if (currentnode.left!=null){
+                    queue.offer(currentnode.left);
+                    result.add(currentnode.left.data);
+                }
+            }
+        }
+        return result;
+    }
+}
+class TreeNode{
+    int data;
+    TreeNode left,right;
+    public TreeNode(int key){
+        key=data;
+        left=right=null;
+    }
+}