Quantum complexity analysis is the study of how hard or easy it is to solve a problem using quantum algorithms, compared to classical algorithms. Quantum complexity analysis is important to understand the advantages and limitations of quantum computing, and to identify the problems that are suitable for quantum algorithms. However, quantum complexity analysis is also very challenging, as it involves many concepts and tools that are different from classical complexity analysis, such as quantum circuits, entanglement, superposition, interference, and measurement. To overcome this challenge, you need to learn the basics of quantum complexity theory, such as the quantum complexity classes, the quantum oracle model, and the quantum query complexity. You also need to use tools such as the quantum Fourier transform, the phase estimation algorithm, and the amplitude amplification algorithm, to design and analyze quantum algorithms.