2024-02-12

pknujsp/BFS/33-이분 그래프.py

@@ -0,0 +1,43 @@
+from sys import *
+from collections import *
+
+
+def bfs(start):
+    q = deque([start])
+    groups[start] = 1
+
+    while q:
+        curr = q.popleft()
+        visited[curr] = True
+
+        for adj in graph[curr]:
+            if visited[adj]:
+                continue
+
+            if not groups[adj]:
+                groups[adj] = -groups[curr]
+                q.append(adj)
+            elif groups[adj] == groups[curr]:
+                return False
+    return True
+
+
+for _ in range(int(stdin.readline())):
+    V, E = map(int, stdin.readline().split())
+    graph = [[] for i in range(V + 1)]
+
+    for _ in range(E):
+        a, b = map(int, stdin.readline().split())
+        graph[a].append(b)
+        graph[b].append(a)
+
+    groups = [0] * (V + 1)
+    visited = [False] * (V + 1)
+    result = None
+
+    for i in range(1, V + 1):
+        if groups[i] == 0 and not bfs(i):
+            result = 'NO'
+            break
+
+    print('YES' if not result else result)