Submission #38415881

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N, M = map(int, input().split())
 
uv = [list(map(int, input().split())) for _ in range(M)]
 
 
from collections import deque, defaultdict
 
def C(N, M, uv):
    edge = defaultdict(list)
    for u, v in uv:
        edge[u].append(v)
        edge[v].append(u)
    
    q = deque([1])
    passed = set([1])
    route = defaultdict(int)
    
    cnt = 1
    while q:
        now = q.popleft()
        if len(edge[now]) > 2:
 
 
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N, M = map(int, input().split())
 
uv = [list(map(int, input().split())) for _ in range(M)]
 
 
from collections import deque, defaultdict
 
def C(N, M, uv):
    edge = defaultdict(list)
    for u, v in uv:
        edge[u].append(v)
        edge[v].append(u)
    
    q = deque([1])
    passed = set([1])
    route = defaultdict(int)
    
    cnt = 1
    while q:
        now = q.popleft()
        if len(edge[now]) > 2:
            return "No"
        for e in edge[now]:
            if e in passed:
                if route[now] != e:
                	return "No"
            else:
                passed.add(e)
                q.append(e)
                route[e] = now
                cnt += 1
    
    return "Yes" if cnt == N else "No"
  
print(C(N, M, uv))

Submission Info

Judge Result