owest-common-ancestor-of-a-binary-tree

public class TreeNode {
     int val;
     TreeNode left;
     TreeNode right;
     TreeNode(int x) { val = x; }
  }
 
class Solution {
    public TreeNode lowestCommonAncestor(TreeNode root, TreeNode p, TreeNode q) {
        
        if(root==null||root==p||root==q)return root;
        TreeNode left=lowestCommonAncestor(root.left, p,q);
        TreeNode right=lowestCommonAncestor(root.right, p,q);
        
        if(left!=null&&right!=null)return root;
        
        if(left!=null)
            return left;
        
        else
            return right;
        
             
    }
}