Algorithm 1: Quantum classifier with respect to quantum encoding

Prepare: Sample set X, unlabeled test point $\widehat{x}$ and quantum classifier circuit $\mathcal{QC}$. Input: graph $G=(V,E)$, adjacent matrix $\Gamma$ 1. for $x_i\in X$$1\le j\le N$, do encode $x_i$ into $|x_i\rangle$ with quantum phase encoder. 2. Applying H to entangle the sample states with $\Gamma$, so that two-level graph state coupling graph is formed. 3. Resort to the circuit $\mathcal{QC}$, for$1\le j\le M$do obtain M classes of weak quantum classifiers $h_j$. 4. Computing the distances between $|\widehat{x}\rangle$ and $|x_i\rangle$ Output: The label y that $|\widehat{x}\rangle$ belongs to.