This lecture provides an overview of quantum algorithms, focusing on their complexity and applications in learning. The instructor begins by discussing the foundational concepts of quantum algorithms, including their motivation from quantum mechanics and their comparison to classical algorithms. Key complexity classes such as BQP and BPP are introduced, along with the challenges of proving the existence of problems that can be efficiently solved by quantum algorithms but not by classical ones. The lecture then delves into specific quantum algorithms, including the hidden subgroup problem and its implications for quantum computing. The instructor highlights selected results from recent research on the quantum complexity of Kronecker coefficients and the role of entanglement in learning. The discussion emphasizes the significance of quantum Fourier transforms and their efficient implementation in quantum circuits. The lecture concludes with insights into ongoing research and open questions in the field, particularly regarding the computational complexity of quantum algorithms and their potential applications in statistical learning.