Submission #65437106

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Source Code Expand

def is_cycle_graph(N, M, graph):
    if N != M:
        return False

    count = 1
    visited = [False] * N
    stack = [0]
    visited[0] = True

    while stack:
        curr = stack.pop()
        for v in graph[curr]:
            if not visited[v]:
                visited[v] = True
                count += 1
                stack.append(v)

    if count != N:
        return False

    return all(len(edges) == 2 for edges in graph)


N, M = map(int, input().split())
graph = [[] for _ in range(N)]

for _ in range(M):
    u, v = map(int, input().split())
    u -= 1
    v -= 1

    graph[u].append(v)
    graph[v].append(u)

print("Yes" if is_cycle_graph(N, M, graph) else "No")

Submission Info

Judge Result