結果

問題 No.1553 Lovely City
ユーザー rlangevin
提出日時 2023-12-02 01:14:02
言語 PyPy3
(7.3.15)
結果
AC  
実行時間 1,227 ms / 2,000 ms
コード長 2,054 bytes
コンパイル時間 443 ms
コンパイル使用メモリ 82,048 KB
実行使用メモリ 165,944 KB
最終ジャッジ日時 2024-09-26 16:11:07
合計ジャッジ時間 27,055 ms
ジャッジサーバーID
(参考情報)
judge4 / judge2
このコードへのチャレンジ
(要ログイン)
ファイルパターン 結果
sample AC * 2
other AC * 26
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 #
プレゼンテーションモードにする

import sys
input = sys.stdin.readline
from heapq import *
from collections import *
def topsort(G, s):
Q = []
count = defaultdict(int)
for u in s:
for v in G[u]:
count[v] += 1
for u in s:
if count[u] == 0:
heappush(Q, u)
anslst = []
while Q:
u = heappop(Q)
anslst.append(u)
for v in G[u]:
count[v] -= 1
if count[v] == 0:
heappush(Q, v)
return anslst
class UnionFind(object):
def __init__(self, n=1):
self.par = [i for i in range(n)]
self.rank = [0 for _ in range(n)]
self.size = [1 for _ in range(n)]
def find(self, x):
if self.par[x] == x:
return x
else:
self.par[x] = self.find(self.par[x])
return self.par[x]
def union(self, x, y):
x = self.find(x)
y = self.find(y)
if x != y:
if self.rank[x] < self.rank[y]:
x, y = y, x
if self.rank[x] == self.rank[y]:
self.rank[x] += 1
self.par[y] = x
self.size[x] += self.size[y]
def is_same(self, x, y):
return self.find(x) == self.find(y)
def get_size(self, x):
x = self.find(x)
return self.size[x]
N, M = map(int, input().split())
G = [[] for i in range(N)]
U = UnionFind(N)
for i in range(M):
u, v = map(int, input().split())
u, v = u - 1, v - 1
U.union(u, v)
G[u].append(v)
S = [set() for _ in range(N)]
for i in range(N):
S[U.find(i)].add(i)
seen = set()
ans = []
for i in range(N):
ui = U.find(i)
if ui in seen:
continue
seen.add(ui)
L = topsort(G, S[ui])
if U.get_size(i) == len(L):
for j in range(len(L) - 1):
ans.append((L[j] + 1, L[j + 1] + 1))
else:
L = list(S[ui])
for j in range(len(L) - 1):
ans.append((L[j] + 1, L[j + 1] + 1))
ans.append((L[-1] + 1, L[0] + 1))
print(len(ans))
for a, b in ans:
print(a, b)
הההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההה
XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
0