100. Same Tree ¶

Time: $O(n)$
Space: $O(h)$

C++JavaPythonJavaScript

class Solution {
 public:
  bool isSameTree(TreeNode* p, TreeNode* q) {
    if (!p || !q)
      return p == q;
    return p->val == q->val &&              //
           isSameTree(p->left, q->left) &&  //
           isSameTree(p->right, q->right);
  }
};

class Solution {
  public boolean isSameTree(TreeNode p, TreeNode q) {
    if (p == null || q == null)
      return p == q;
    return p.val == q.val &&          //
        isSameTree(p.left, q.left) && //
        isSameTree(p.right, q.right);
  }
}

class Solution:
  def isSameTree(self, p: TreeNode | None, q: TreeNode | None) -> bool:
    if not p or not q:
      return p == q
    return (p.val == q.val and
            self.isSameTree(p.left, q.left) and
            self.isSameTree(p.right, q.right))

var isSameTree = function(p, q) {
  if (!p && !q) return true;
  if (!p || !q || p.val !== q.val) return false;
  return isSameTree(p.left, q.left) && isSameTree(p.right, q.right);
};