Amplification example with Grover

justfile

@@ -11,8 +11,7 @@ ci:
 
 # List the available examples
 list:
-    @ls -lA ./src/examples/ | tail -n +2 | awk '{print $9}' | sed 's/.py//' | tr '\n' ' '
-    @echo
+    @ls -lA ./src/examples/ | tail -n +2 | awk '{print $9}' | sed 's/.py//'
 
 # Run a selected example from the examples folder
 run example:

src/examples/grover_search_known_m.py

@@ -0,0 +1,73 @@
+'''Find the models of an ASP program using the naive Grover search algorithm.
+'''
+
+from src import qasp
+
+# ASP program
+PRGM = '''
+    p :- not q.
+    q :- not p.
+    r :- p.
+    r :- q.
+'''
+
+# Hardcoded list of stable models
+STABLE_MODELS = [
+    [('p', True), ('q', False), ('r', True)],  # {p, r}
+    [('p', False), ('q', True), ('r', True)],  # {q, r}
+]
+
+
+def pause():
+    '''Pause the program execution and wait for the user to press a key to continue.
+    '''
+    _ = input("Press the <ENTER> key to continue...")
+    print()
+
+
+def tab(lines: str, striplines: bool = False) -> str:
+    '''Return a variant of the input string indented by one level.
+
+    #### Arguments
+        lines (str): Lines to be indented.
+        striplines (bool): Whether to strip() individual lines before re-joining. Defaults to False.
+
+    #### Return
+        str: Indented variant of the provided string.
+    '''
+    return '\n'.join([
+        '    ' + (line.strip() if striplines else line)
+        for line in lines.splitlines(False)
+    ])
+
+
+if __name__ == '__main__':
+    print(f'ASP program:\n{tab(PRGM.strip(), striplines = True)}\n')
+    pause()
+
+    # Program parameters
+    N = len(STABLE_MODELS[0])
+    M = len(STABLE_MODELS)
+    print(f'Number of variables: {N}.')
+    print(f'Number of stable models: {M}.')
+    print()
+    pause()
+
+    # Initialization algorithm
+    algorithm = qasp.problems.amplification.alg_grover(N)  # Walsh-Hadamard
+    print(f'Initialization algorithm:\n{tab(str(algorithm.draw()))}\n')
+    pause()
+
+    # Oracle
+    oracle = qasp.oracle.from_asp_stable_models(STABLE_MODELS)
+    print(f'Quantum oracle:\n{tab(str(oracle[1].draw()))}\n')
+    pause()
+
+    # Simulation
+    (circuit, iters, stable_model) = qasp.problems.amplification.exec_find_one_known_m(
+        algorithm, oracle, M)
+    print(f'Circuit:\n\n{circuit.draw()}')
+    pause()
+    print(f'Found stable model: {stable_model}.')
+    print(f'Number of iterations: {iters}.')
+    print()

src/qasp/problems/amplification.py

@@ -160,7 +160,11 @@ def __measure_to_model(measurements: str, var_names: str) -> Model:
     return model
 
 
-def exec_find_one_known_m(algorithm: QuantumCircuit, oracle: Oracle, m: int) -> tuple[int, Model]:
+def exec_find_one_known_m(
+    algorithm: QuantumCircuit,
+    oracle: Oracle,
+    m: int
+) -> tuple[QuantumCircuit, int, Model]:
     '''Simulate the amplitude amplification circuit to find one solution to the problem.
 
     #### Arguments
@@ -169,7 +173,8 @@ def exec_find_one_known_m(algorithm: QuantumCircuit, oracle: Oracle, m: int) ->
         m (int): (Known) number of solutions.
 
     #### Return
-        tuple[int, Model]: Found solution and number of iterations performed.
+        tuple[QuantumCircuit, int, Model]: Used circuit, number of iterations performed, and found \
+            solution.
     '''
     (c_oracle, q_oracle) = oracle
 
@@ -181,7 +186,6 @@ def exec_find_one_known_m(algorithm: QuantumCircuit, oracle: Oracle, m: int) ->
 
     # Build circuit
     circ = circuit_optimal(algorithm, q_oracle, m)
-    print(f'Circuit:\n{circ.draw()}\n')
 
     # Run simulation
     model, iters = None, 0
@@ -194,7 +198,7 @@ def exec_find_one_known_m(algorithm: QuantumCircuit, oracle: Oracle, m: int) ->
             break
 
     # Map output to readable format
-    return (iters, model)
+    return (circ, iters, model)
 
 
 def exec_find_one_unknown_m(