Correct coloured_nodes type annotation

qermit/coherent_pauli_checks/box_clifford_subcircuits.py

@@ -30,7 +30,7 @@ def _command_is_clifford(command: Command) -> bool:
     return False
 
 
-def _get_clifford_commands(command_list: list[Command]) -> set[int]:
+def _get_clifford_commands(command_list: list[Command]) -> list[int]:
     """Given a list of commands, return a set of indexes of that list
     corresponding to those commands which are Clifford gates.
 
@@ -39,9 +39,9 @@ def _get_clifford_commands(command_list: list[Command]) -> set[int]:
     :return: Indexes in the list which correspond to commands in the
         list which are Clifford.
     """
-    return {
+    return [
         i for i, command in enumerate(command_list) if _command_is_clifford(command)
-    }
+    ]
 
 
 def _give_nodes_subdag(dag: nx.DiGraph, node_subdag: dict[int, int]) -> list[int]:

qermit/coherent_pauli_checks/monochromatic_convex_subdag.py

@@ -1,4 +1,4 @@
-from itertools import permutations
+from itertools import combinations
 from typing import Any
 
 import networkx as nx  # type: ignore
@@ -66,7 +66,7 @@ def _subdag_successors(
 
 
 def get_monochromatic_convex_subdag(
-    dag: nx.DiGraph, coloured_nodes: set[Any]
+    dag: nx.DiGraph, coloured_nodes: list[Any]
 ) -> dict[Any, int]:
     """Retrieve assignment of coloured nodes to sub-DAGs.
     The assignment aims to minimise the number of sub-DAGs.
@@ -75,7 +75,6 @@ def get_monochromatic_convex_subdag(
     :param coloured_nodes: The nodes which are coloured.
     :return: Map from node to the sub-DAG to which it belongs.
     """
-    node_subdag = {node: i for i, node in enumerate(coloured_nodes)}
 
     node_descendants = {node: nx.descendants(dag, node) for node in dag.nodes}
     for node in node_descendants.keys():
@@ -124,15 +123,14 @@ def _can_merge(
 
         return True
 
+    node_subdag = {node: i for i, node in enumerate(coloured_nodes)}
+
     subgraph_merged = True
     while subgraph_merged:
         subgraph_merged = False
 
         # Try to merge all pairs of sub-DAGs
-        for subdag_one, subdag_two in permutations(node_subdag.values(), 2):
-            if subdag_one == subdag_two:
-                continue
-
+        for subdag_one, subdag_two in combinations(set(node_subdag.values()), 2):
             if _can_merge(
                 dag=dag,
                 subdag_one=subdag_one,