Add Python implementation of GraphX (Hash + Graph + BFS)

GraphX.py

@@ -0,0 +1,82 @@
+# GraphX.py
+# Clean Pythonic version of GraphX.cpp
+
+from collections import defaultdict, deque
+
+
+class Hash:
+    def __init__(self):
+        self._table = {}
+        self._counter = 0
+
+    def get(self, key):
+        if isinstance(key, int):
+            key = (key, 0, 0)
+        elif isinstance(key, tuple):
+            if len(key) == 2:
+                key = (key[0], key[1], 0)
+            elif len(key) == 3:
+                key = key
+            else:
+                raise TypeError("Invalid tuple length for key.")
+        else:
+            raise TypeError("Invalid key type.")
+
+        if key not in self._table:
+            self._table[key] = self._counter
+            self._counter += 1
+
+        return self._table[key]
+
+    def __call__(self, key):
+        return self.get(key)
+
+
+class Graph:
+    def __init__(self, is_directed=True):
+        self.is_directed = is_directed
+        self.h = Hash()
+        self.adj = defaultdict(list)
+
+    def _id(self, x):
+        return self.h(x)
+
+    def add_edge(self, u, v, weight=0):
+        uid = self._id(u)
+        vid = self._id(v)
+        self.adj[uid].append((vid, weight))
+        if not self.is_directed:
+            self.adj[vid].append((uid, weight))
+
+
+class BFS:
+    def __init__(self, graph):
+        self.g = graph
+        self.clear()
+
+    def clear(self):
+        self.dist = {}
+        self.vis = {}
+
+    def run(self, source):
+        start = self.g.h(source)
+
+        q = deque([start])
+        self.dist = {start: 0}
+        self.vis = {start: True}
+
+        while q:
+            cur = q.popleft()
+            for nxt, _ in self.g.adj[cur]:
+                if nxt not in self.vis:
+                    self.vis[nxt] = True
+                    self.dist[nxt] = self.dist[cur] + 1
+                    q.append(nxt)
+
+    def min_dist(self, target):
+        tid = self.g.h(target)
+        return self.dist.get(tid, -1)
+
+    def is_visited(self, target):
+        tid = self.g.h(target)
+        return self.vis.get(tid, False)