title: How to determine if two binary trees are equal or different
body: <p>The picture below is the case of different binary trees that can be made with 3 nodes.</p>
  <p><a href="https://i.stack.imgur.com/j1dEI.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/j1dEI.png" alt="enter image description here" /></a></p>
  <p>But why is the following case not included in the number of cases?</p>
  <p><a href="https://i.stack.imgur.com/knzRL.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/knzRL.png" alt="enter image description here" /></a></p>
  <p>Is it the same case as the third case from the left in the picture above? If so, I think the parent-child relationship will be different.</p>
  <p>I'd appreciate it if you could tell me how to determine how binary trees are equal to or different from each other.</p>