A quantum algorithm uses superposition and interference, and sometimes entanglement, to answer a specific question in fewer steps than the best classical method we know.
Each lesson below derives one algorithm in full. Deutsch-Jozsa separates constant and balanced functions with a single query. Grover search finds a marked item in an unordered list. The quantum Fourier transform is the engine of order finding, and Shor's algorithm turns that order into the prime factors of a composite integer.
