結果

問題 No.2780 The Bottle Imp
ユーザー 回転
提出日時 2025-07-30 01:27:54
言語 PyPy3
(7.3.15)
結果
AC  
実行時間 697 ms / 2,000 ms
コード長 3,615 bytes
コンパイル時間 375 ms
コンパイル使用メモリ 82,520 KB
実行使用メモリ 276,656 KB
最終ジャッジ日時 2025-07-30 01:28:09
合計ジャッジ時間 14,099 ms
ジャッジサーバーID
（参考情報） 		judge5 / judge3
このコードへのチャレンジ
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ファイルパターン 結果
sample AC * 4
other AC * 40
権限があれば一括ダウンロードができます

ソースコード

diff # 

#from atcoder.scc import SCCGraph

import sys
import typing

class CSR:
    def __init__(
            self, n: int, edges: typing.List[typing.Tuple[int, int]]) -> None:
        self.start = [0] * (n + 1)
        self.elist = [0] * len(edges)

        for e in edges:
            self.start[e[0] + 1] += 1

        for i in range(1, n + 1):
            self.start[i] += self.start[i - 1]

        counter = self.start.copy()
        for e in edges:
            self.elist[counter[e[0]]] = e[1]
            counter[e[0]] += 1

class _SCCGraph:
    '''
    Reference:
    R. Tarjan,
    Depth-First Search and Linear Graph Algorithms
    '''

    def __init__(self, n: int) -> None:
        self._n = n
        self._edges: typing.List[typing.Tuple[int, int]] = []

    def num_vertices(self) -> int:
        return self._n

    def add_edge(self, from_vertex: int, to_vertex: int) -> None:
        self._edges.append((from_vertex, to_vertex))

    def scc_ids(self) -> typing.Tuple[int, typing.List[int]]:
        g = CSR(self._n, self._edges)
        now_ord = 0
        group_num = 0
        visited = []
        low = [0] * self._n
        order = [-1] * self._n
        ids = [0] * self._n

        sys.setrecursionlimit(max(self._n + 1000, sys.getrecursionlimit()))

        def dfs(v: int) -> None:
            nonlocal now_ord
            nonlocal group_num
            nonlocal visited
            nonlocal low
            nonlocal order
            nonlocal ids

            low[v] = now_ord
            order[v] = now_ord
            now_ord += 1
            visited.append(v)
            for i in range(g.start[v], g.start[v + 1]):
                to = g.elist[i]
                if order[to] == -1:
                    dfs(to)
                    low[v] = min(low[v], low[to])
                else:
                    low[v] = min(low[v], order[to])

            if low[v] == order[v]:
                while True:
                    u = visited[-1]
                    visited.pop()
                    order[u] = self._n
                    ids[u] = group_num
                    if u == v:
                        break
                group_num += 1

        for i in range(self._n):
            if order[i] == -1:
                dfs(i)

        for i in range(self._n):
            ids[i] = group_num - 1 - ids[i]

        return group_num, ids

    def scc(self) -> typing.List[typing.List[int]]:
        ids = self.scc_ids()
        group_num = ids[0]
        counts = [0] * group_num
        for x in ids[1]:
            counts[x] += 1
        groups: typing.List[typing.List[int]] = [[] for _ in range(group_num)]
        for i in range(self._n):
            groups[ids[1][i]].append(i)

        return groups



class SCCGraph:
    def __init__(self, n: int = 0) -> None:
        self._internal = _SCCGraph(n)

    def add_edge(self, from_vertex: int, to_vertex: int) -> None:
        n = self._internal.num_vertices()
        assert 0 <= from_vertex < n
        assert 0 <= to_vertex < n
        self._internal.add_edge(from_vertex, to_vertex)

    def scc(self) -> typing.List[typing.List[int]]:
        return self._internal.scc()


edge = []
N = int(input())
G = SCCGraph(N)
for i in range(N):
    m,*A = list(map(lambda x:int(x)-1,input().split()))
    edge.append(A[:])
    for j in A:G.add_edge(i,j)

scc = G.scc()
can_next = set([i for i in range(N)])
if(0 not in scc[0]):
    print("No")
    exit()

for i in scc:
    if(i[0] not in can_next):
        print("No")
        exit()

    can_next = set()
    for j in i:
        for k in edge[j]:
            can_next.add(k)

print("Yes")
0