One question, one answer
A CX with q0 as control and q1 as target is the oracle for a hidden one-bit function f, writing f into q1. This particular f is balanced — f(0) ≠ f(1) — and a classical computer needs two queries to know that. Build the whole circuit, using that CX ONCE and only once, so that q0 reads |1⟩ on every shot: q0 = 1 means balanced, and you asked once. Par is 5.
Stuck on the concept? Read Interference: Where the Power Comes From.
Select a gate to see what it does, then tap a wire — or Tab to a wire and press Enter — to place it.
Pick a gate, then tap a cell — or Tab into the grid and use the arrow keys and Enter — to place it.
Generate a fresh target state drill at this difficulty. Every generated puzzle is verified solvable by execution before you see it — the generator runs its own solution through the same simulator and grader that will judge yours.