Submission #6435833

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Source Code Expand

N,M = map(int,input().split())
KL = [list(map(int,input().split())) for _ in [0]*N]

E = [[] for _ in [0]*(N+M)]
for i,kl in enumerate(KL):
    for l in kl[1:]:
        E[i].append(N+l-1)
        E[N+l-1].append(i)

start = 0
d = [-1]*(N+M) #d[0] - d[N-1]:人, d[N] - D[N+M-1]:言語
d[start] = 0
q = [start]
while q:
    i = q.pop()
    for j in E[i]:
        if d[j]==-1:continue
        d[j] = d[i]+1
        q.append(j)

ans = True
for b in d[:N]:
    ans = ans and (b>=0)
print("YES" if ans else "NO")

Submission Info

Judge Result