Quantum Computing Code Challenges & Tips

1. Write a quantum circuit in Qiskit to create a Bell state and measure the qubits.

2. Implement a Grover's search algorithm to find a marked item in an unsorted database of 8 items using Qiskit.

3. Create a function that simulates a simple quantum teleportation protocol. Demonstrate it using a quantum simulator.

4. Given a quantum circuit defined in Qiskit, write code to visualize the circuit architecture and draw its corresponding diagram.

5. Implement a quantum random walk on a cycle of size N and compute the probability distribution of the walk after a given number of steps.

6. Write a program that performs the Quantum Fourier Transform (QFT) on a 3-qubit system and verifies the output.

7. Create an implementation of the Quantum Approximate Optimization Algorithm (QAOA) for a small instance of Max-Cut problem using Qiskit.

8. Write a function that takes a quantum state vector and applies a series of Pauli gates to it, returning the resulting state vector.

9. Construct a quantum circuit that simulates a density matrix evolution under the influence of a Hamiltonian for a given time.

10. Implement a Quantum Key Distribution protocol (like BB84) and demonstrate its operation through simulated quantum states.