def is_valid(state, edges): for u, v in edges: if ((state >> u) & 1) and ((state >> v) & 1): return False return Truedef main: M, N = map(int, input.split) edges = for _ in range(N): u, v = map(int, input.split) # 转换为从0开始的索引 edges.append((u - 1, v - 1)) total = 0 for state in range(1摘要：def is_valid(state, edges): for u, v in edges: if ((state >> u) & 1) and ((state >> v) & 1): return False return Truedef main: M,
来源：然然课堂