  Quantum algorithms are demonstrated to outperform classical algorithms for
certain problems and thus are promising candidates for efficient information
processing. Herein we aim to provide a brief and popular introduction to
quantum algorithms for both the academic community and the general public with
interest. We start from elucidating quantum parallelism, the basic framework of
quantum algorithms and the difficulty of quantum algorithm design. Then we
mainly focus on a historical overview of progress in quantum algorithm research
over the past three to four decades. Finally, we clarify two common questions
about the study of quantum algorithms, hoping to stimulate readers for further
exploration.
