Submission #6436038

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Source Code Expand

import heapq
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][N+l-1] = 1
        E[N+l-1][i] = 1

def Dijkstra(N,E,start):
    d = [-1]*N
    q = [(0,start-1)]
    while q:
        ci,i = heapq.heappop(q)
        if d[i]!= -1:continue
        d[i] = ci
        for j,cj in E[i].items():
            if d[j]!=-1:continue
            heapq.heappush(q,(ci+cj,j))
    return d

d = Dijkstra(N+M,E,0)
ans = d[:N].count(-1)==0
print("YES" if ans else "NO")

Submission Info

Judge Result