結果

問題 No.2780 The Bottle Imp
コンテスト
ユーザー detteiuu
提出日時 2024-09-02 22:46:36
言語 PyPy3
(7.3.15)
結果
AC  
実行時間 338 ms / 2,000 ms
コード長 4,225 bytes
コンパイル時間 259 ms
コンパイル使用メモリ 82,584 KB
実行使用メモリ 169,620 KB
最終ジャッジ日時 2024-09-02 22:46:44
合計ジャッジ時間 7,728 ms
ジャッジサーバーID
（参考情報） 		judge4 / judge5
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 collections import deque

class UnionFind:
    def __init__(self,n):
        self.n = n
        self.parent_size = [-1]*n
 
    def leader(self,a):
        if self.parent_size[a] < 0:
            return a
        self.parent_size[a] = self.leader(self.parent_size[a])
        return self.parent_size[a]
 
    def merge(self,a,b):
        x, y = self.leader(a), self.leader(b)
        if x == y:
            return 
        if abs(self.parent_size[x]) < abs(self.parent_size[y]):
            x, y = y, x
        self.parent_size[x] += self.parent_size[y]
        self.parent_size[y] = x
        return 
 
    def same(self,a,b):
        return self.leader(a) == self.leader(b)
 
    def size(self,a):
        return abs(self.parent_size[self.leader(a)])
 
    def groups(self):
        result = [[] for _ in range(self.n)]
        for i in range(self.n):
            result[self.leader(i)].append(i)
        return [r for r in result if r != []]
    
def scc(N,edges):
    M=len(edges)
    start=[0]*(N+1)
    elist=[0]*M
    for e in edges:
        start[e[0]+1]+=1
    for i in range(1,N+1):
        start[i]+=start[i-1]
    counter=start[:]
    for e in edges:
        elist[counter[e[0]]]=e[1]
        counter[e[0]]+=1
    visited=[]
    low=[0]*N
    Ord=[-1]*N
    ids=[0]*N
    NG=[0,0]
    def dfs(v):
        stack=[(v,-1,0),(v,-1,1)]
        while stack:
            v,bef,t=stack.pop()
            if t:
                if bef!=-1 and Ord[v]!=-1:
                    low[bef]=min(low[bef],Ord[v])
                    stack.pop()
                    continue
                low[v]=NG[0]
                Ord[v]=NG[0]
                NG[0]+=1
                visited.append(v)
                for i in range(start[v],start[v+1]):
                    to=elist[i]
                    if Ord[to]==-1:
                        stack.append((to,v,0))
                        stack.append((to,v,1))
                    else:
                        low[v]=min(low[v],Ord[to])
            else:
                if low[v]==Ord[v]:
                    while(True):
                        u=visited.pop()
                        Ord[u]=N
                        ids[u]=NG[1]
                        if u==v:
                            break
                    NG[1]+=1
                low[bef]=min(low[bef],low[v])
    for i in range(N):
        if Ord[i]==-1:
            dfs(i)
    for i in range(N):
        ids[i]=NG[1]-1-ids[i]
    group_num=NG[1]
    counts=[0]*group_num
    for x in ids:
        counts[x]+=1
    groups=[[] for i in range(group_num)]
    for i in range(N):
        groups[ids[i]].append(i)
    return groups

from types import GeneratorType

def bootstrap(f, stack=[]):
    def wrappedfunc(*args, **kwargs):
        if stack:
            return f(*args, **kwargs)
        to = f(*args, **kwargs)
        while True:
            if type(to) is GeneratorType:
                stack.append(to)
                to = next(to)
            else:
                stack.pop()
                if not stack:
                    break
                to = stack[-1].send(to)
        return to
    return wrappedfunc

N = int(input())
edge = []
zero = 0
for i in range(N):
    MA = list(map(int, input().split()))
    M = MA[0]
    if M == 0:
        zero += 1
    if zero >= 2:
        exit(print("No"))
    A = MA[1:]
    for j in range(M):
        edge.append((i, A[j]-1))

SCC = scc(N, edge)
L = len(SCC)
UF = UnionFind(N)
for s in SCC:
    if len(s) >= 2:
        for i in range(len(s)-1):
            UF.merge(s[i], s[i+1])
G = [set() for _ in range(N)]
for e in edge:
    u, v = e
    if not UF.same(u, v):
        G[UF.leader(u)].add(UF.leader(v))
for i in range(N):
    G[i] = list(G[i])

@bootstrap
def dfs(n):
    visited[UF.leader(n)] = True
    for v in G[UF.leader(n)]:
        if not visited[UF.leader(v)]:
            yield dfs(UF.leader(v))
    S.append(UF.leader(n))
    yield

visited = [False]*N
S = []
dfs(0)
S = S[::-1]
cnt = 0
for i in range(N):
    if UF.leader(i) == i:
        cnt += 1
if cnt > len(S):
    exit(print("No"))

for i in range(len(S)-1):
    for j in G[S[i]]:
        if S[i+1] == j:
            break
    else:
        print("No")
        break
else:
    print("Yes")
0