added LCA of Binary Tree

Author: saihariG

Trees/LCAofBinaryTree.java

@@ -0,0 +1,27 @@
+package Trees;
+
+public class LCAofBinaryTree {
+
+    static class TreeNode {
+        private int val;
+        private TreeNode left,right;
+    }
+
+    public TreeNode lowestCommonAncestor(TreeNode root, TreeNode p, TreeNode q) {
+        if(root.val == p.val || root.val == q.val) return root;
+
+        if(root.left == null && root.right == null) return null;
+
+        TreeNode left = null , right = null;
+
+        if(root.left != null)
+            left = lowestCommonAncestor(root.left,p,q);
+        if(root.right != null)
+            right = lowestCommonAncestor(root.right,p,q);
+        if(left != null && right != null)
+            return root;
+
+        // if both p and q present in the right subtree
+        return (left==null) ? right : left;
+    }
+}