Same Binary Tree

Given two binary trees, write a function to check if they are equal or not.
Two binary trees are considered equal if they are structurally identical and the nodes have the same value.

public class Same_Binary_Tree {
 public class TreeNode{
  int val;
  TreeNode left;
  TreeNode right;
  TreeNode(int x) {
   val = x;
  }
 }
 public boolean isSameTree(TreeNode p, TreeNode q) {
        if (p == null && q == null) {
         return true;
        } else if (p != null && q != null) {
         if (p.val == q.val) {
          return isSameTree(p.left, q.left) &&
            isSameTree(p.right, q.right);
         }
        } else {
         return false;
        }
        return false;
        
    }
}