C - Cards Query Problem https://atcoder.jp/contests/abc298/tasks/abc298_c

abc298_c.py

N = int(input())
Q = int(input())
boxes = [[] for _ in range(N + 1)]
cards = {}
for _ in range(Q):
    t, *q = map(int, input().split())
    if t == 1:
        i, j = q
        boxes[j].append(i)
        if i not in cards:
            cards[i] = set()
        cards[i].add(j)
    elif t == 2:
        i = q[0]
        print(*sorted(boxes[i]))
    else:
        i = q[0]
        print(*sorted(cards[i]))