Create count-the-number-of-complete-components.py

Author: kamyu104

Python/count-the-number-of-complete-components.py

@@ -0,0 +1,36 @@
+# Time:  O(n)
+# Space: O(n)
+
+# bfs
+class Solution(object):
+    def countCompleteComponents(self, n, edges):
+        """
+        :type n: int
+        :type edges: List[List[int]]
+        :rtype: int
+        """
+        def bfs(u):
+            if lookup[u]:
+                return False
+            v_cnt = e_cnt = 0
+            lookup[u] = True
+            q = [u]
+            while q:
+                new_q = []
+                v_cnt += len(q)
+                for u in q:
+                    e_cnt += len(adj[u])
+                    for v in adj[u]:
+                        if lookup[v]:
+                            continue
+                        lookup[v] = True
+                        new_q.append(v)
+                q = new_q
+            return v_cnt*(v_cnt-1) == e_cnt
+
+        adj = [[] for _ in xrange(n)]
+        for u, v in edges:
+            adj[u].append(v)
+            adj[v].append(u)
+        lookup = [False]*n
+        return sum(bfs(u) for u in xrange(n) if not lookup[u])