Balanced oracle: f(x) = x0 XOR x1
Expected output (exact): {'11': 1.0}
Expected output (1024 shots): {'11': 1024}
→ At least one bit is 1, so f is BALANCED. Correct!

Constant oracle: f(x) = 0
Expected output (exact): {'00': 1.0}
Expected output (1024 shots): {'00': 1024}
→ All bits are 0, so f is CONSTANT. Correct!

Summary:
- If ALL measured bits are 0 → f is constant
- If ANY measured bit is 1 → f is balanced
- The algorithm NEVER gives a wrong answer
- A classical algorithm needs up to 2^(n-1) + 1 queries; this uses exactly 1