Check if two trees are identical?

Short answer: bool IsIdentical(TreeNode p, TreeNode q) { if (p == null && q == null) return true; if (p == null || q == null) return false; if (p.val != q.val) return false; return IsIdentical(p.left, q.left) && IsIdentical(p.right, q.right); } Explanation: Recursive check values and structure for equality.

Example code

bool IsIdentical(TreeNode p, TreeNode q) { if (p == null && q == null) return true;
if (p == null || q == null) return false;
if (p.val != q.val) return false;
return IsIdentical(p.left, q.left) && IsIdentical(p.right, q.right); } Explanation: Recursive check values and structure for equality.

Real-world example (ShopNest)

In coding rounds, state complexity aloud, write a clear ShopNest-flavored example (orders, carts), then handle edge cases (empty list, null, overflow).

Say this in the interview

1. Define — one clear sentence (the short answer above).
2. Example — relate it to a project like ShopNest or your real work.
3. Trade-off — when you would not use it.