feat: number-of-connected-components-in-an-undirected-graph problem

Author: hu6r1s

number-of-connected-components-in-an-undirected-graph/hu6r1s.py

@@ -0,0 +1,43 @@
+class Solution:
+    # def countComponents(self, n: int, edges: List[List[int]]) -> int:
+    #     graph = [[] for _ in range(n)]
+    #     for node, adj in edges:
+    #         graph[node].append(adj)
+    #         graph[adj].append(node)
+
+    #     visited = set()
+
+    #     def dfs(node):
+    #         visited.add(node)
+    #         for adj in graph[node]:
+    #             if adj not in visited:
+    #                 dfs(adj)
+
+    #     cnt = 0
+    #     for node in range(n):
+    #         if node not in visited:
+    #             cnt += 1
+    #             dfs(node)
+    #     return cnt
+
+
+    def countComponents(self, n: int, edges: List[List[int]]) -> int:
+        graph = [[] for _ in range(n)]
+        for node, adj in edges:
+            graph[node].append(adj)
+            graph[adj].append(node)
+
+        cnt = 0
+        visited = set()
+        for node in range(n):
+            if node in visited:
+                continue
+            cnt += 1
+            queue = deque([node])
+            while queue:
+                node = queue.pop()
+                visited.add(node)
+                for adj in graph[node]:
+                    if adj not in visited:
+                        queue.append(adj)
+        return cnt