1167C - News Distribution - CodeForces Solution

import sys
from collections import deque

toks = (tok for tok in sys.stdin.read().split())



N = int(next(toks))
K = int(next(toks))



adjacency_lists = [[] for _ in range(N)]

for i in range(K):
    group_size = int(next(toks))

    if group_size == 0:
        continue
    if group_size == 1:
        next(toks)
        continue
    
    prev_person = None
    for _ in range(group_size):
                cur_person = int(next(toks))-1

                        if prev_person != None:
            adjacency_lists[prev_person].append(cur_person)
            adjacency_lists[cur_person].append(prev_person)
            
        prev_person = cur_person

comps = []
comp_of_vertex = [None for _ in range(N)]

for vertex in range(N):
            if comp_of_vertex[vertex] == None:
        comps.append([vertex])

                bfs_q = deque()
        bfs_q.append(vertex)
                        comp_of_vertex[vertex] = len(comps)-1

        while len(bfs_q) > 0:
            cur_vertex = bfs_q.popleft()

            for new_vertex in adjacency_lists[cur_vertex]:
                                                                                                if comp_of_vertex[new_vertex] == None:
                    comps[len(comps)-1].append(new_vertex)
                    comp_of_vertex[new_vertex] = len(comps)-1
                    bfs_q.append(new_vertex)
                    
for i in range(N):
    if i > 0:
        sys.stdout.write(" ")
    sys.stdout.write(str(len(comps[comp_of_vertex[i]])))
sys.stdout.write("\n")