  An increasing number of communication and computational schemes with quantum
advantages have recently been proposed, which implies that quantum technology
has fertile application prospects. However, demonstrating these schemes
experimentally continues to be a central challenge because of the difficulty in
preparing high-dimensional states or highly entangled states. In this study, we
introduce and analyse a quantum coupon collector protocol by employing coherent
states and simple linear optical elements, which was successfully demonstrated
using realistic experimental equipment. We showed that our protocol can
significantly reduce the number of samples needed to learn a specific set
compared with the classical limit of the coupon collector problem. We also
discuss the potential values and expansions of the quantum coupon collector by
constructing a quantum blind box game. The information transmitted by the
proposed game also broke the classical limit. These results strongly prove the
advantages of quantum mechanics in machine learning and communication
complexity.
