add missing include statement in distance.h (#423)

* add missing include statement in distance.h

* weight syntax change

* fix prob assignment

---------

Co-authored-by: James Wootton <decodoku@gmail.com>

src/qiskit_qec/analysis/distance.h

@@ -5,6 +5,7 @@
 #include <vector>
 #include <set>
 #include <exception>
+#include <iterator>
 
 #include "linear.h"
 #include "combinations.h"

src/qiskit_qec/analysis/distance.py

@@ -113,14 +113,12 @@ def _minimum_distance_2_python(stabilizer: np.ndarray, gauge: np.ndarray, max_we
     for row in range(xl.shape[0]):
         for w in range(1, max_weight + 1):
             if _distance_test(stabilizer.astype(int), xl[row].astype(int), w):
-                if w < weight:
-                    weight = w
+                weight = min(weight, w)
                 break
     for row in range(zl.shape[0]):
         for w in range(1, max_weight + 1):
             if _distance_test(stabilizer.astype(int), zl[row].astype(int), w):
-                if w < weight:
-                    weight = w
+                weight = min(weight, w)
                 break
     if weight < max_weight + 1:
         return weight

src/qiskit_qec/decoders/decoding_graph.py

@@ -322,7 +322,7 @@ def weight_syndrome_graph(self, counts, method: str = METHOD_SPITZ):
 
         boundary_nodes = []
         for n, node in enumerate(self.graph.nodes()):
-            if node.is_boundary:
+            if node.is_logical:
                 boundary_nodes.append(n)
 
         for edge in self.graph.edge_list():