結果

問題 No.1983 [Cherry 4th Tune C] 南の島のマーメイド
ユーザー tamato
提出日時 2022-06-17 22:25:19
言語 PyPy3
(7.3.15)
結果
WA  
実行時間 -
コード長 5,679 bytes
コンパイル時間 420 ms
コンパイル使用メモリ 82,436 KB
実行使用メモリ 260,012 KB
最終ジャッジ日時 2024-10-09 08:35:51
合計ジャッジ時間 36,715 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
(要ログイン)
ファイルパターン 結果
other AC * 40 WA * 1
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

mod = 998244353
def main():
import sys
from collections import deque
input = sys.stdin.buffer.readline
# return: articulation points, bridges
# The graph must be connected.
def lowlink(adj, root=1):
N = len(adj) - 1
order = [N + 1] * (N + 1)
low = [N + 1] * (N + 1)
AP = []
bridge = []
st = [root]
cnt = 1
par = [0] * (N + 1)
seq = []
while st:
v = st.pop()
if order[v] != N + 1:
continue
order[v] = cnt
seq.append(v)
low[v] = cnt
cnt += 1
for u in adj[v]:
if order[u] < cnt:
if par[v] != u:
low[v] = min(low[v], order[u])
continue
else:
par[u] = v
st.append(u)
child = [[] for _ in range(N + 1)]
for v in range(1, N + 1):
child[par[v]].append(v)
seq.reverse()
for v in seq:
for u in child[v]:
low[v] = min(low[v], low[u])
# bridge
for p in range(1, N + 1):
for c in child[p]:
if order[p] < low[c]:
bridge.append((p, c))
# articulation point
for v in range(1, N + 1):
if v == root:
if len(child[v]) > 1:
AP.append(v)
else:
for c in child[v]:
if order[v] <= low[c]:
AP.append(v)
break
return AP, bridge
# idx_new[v]: adj_new()v
def two_edge_connected_components(adj, bridge):
N = len(adj) - 1
cnt = 0
idx_new = [-1] * (N + 1)
seen = [0] * (N + 1)
B = set()
for u, v in bridge:
B.add(u * (N + 1) + v)
B.add(v * (N + 1) + u)
for v0 in range(1, N + 1):
if seen[v0]:
continue
seen[v0] = 1
st = [v0]
cnt += 1
while st:
v = st.pop()
idx_new[v] = cnt
for u in adj[v]:
if not seen[u]:
if v * (N + 1) + u in B:
continue
seen[u] = 1
st.append(u)
adj_new = [[] for _ in range(cnt + 1)]
for u, v in bridge:
u_new = idx_new[u]
v_new = idx_new[v]
adj_new[u_new].append(v_new)
adj_new[v_new].append(u_new)
return adj_new, idx_new
class UnionFind():
def __init__(self, n):
self.n = n
self.root = [-1] * (n + 1)
self.rnk = [0] * (n + 1)
def find_root(self, x):
while self.root[x] >= 0:
x = self.root[x]
return x
def unite(self, x, y):
x = self.find_root(x)
y = self.find_root(y)
if x == y:
return
elif self.rnk[x] > self.rnk[y]:
self.root[x] += self.root[y]
self.root[y] = x
else:
self.root[y] += self.root[x]
self.root[x] = y
if self.rnk[x] == self.rnk[y]:
self.rnk[y] += 1
def isSameGroup(self, x, y):
return self.find_root(x) == self.find_root(y)
def size(self, x):
return -self.root[self.find_root(x)]
N, M, Q = map(int, input().split())
adj_ori = [[] for _ in range(N + 1)]
UF_ori = UnionFind(N)
for _ in range(M):
a, b = map(int, input().split())
adj_ori[a].append(b)
adj_ori[b].append(a)
UF_ori.unite(a, b)
adj_dict = {}
idx_dict = {}
UF = UnionFind(N)
seen = [0] * (N + 1)
V0 = [-1] * (N + 1)
for v0 in range(1, N + 1):
if seen[v0]:
continue
que = deque()
que.append(v0)
seen[v0] = 1
seq = []
while que:
v = que.popleft()
V0[v] = v0
seq.append(v)
for u in adj_ori[v]:
if not seen[u]:
que.append(u)
seen[u] = 1
idx = {v: i+1 for i, v in enumerate(seq)}
idx_dict[v0] = idx
NN = len(seq)
adj = [[] for _ in range(NN + 1)]
for v in seq:
i = idx[v]
for u in adj_ori[v]:
j = idx[u]
adj[i].append(j)
adj_dict[v0] = adj
AP, bridge = lowlink(adj, root=1)
adj_new, idx_new = two_edge_connected_components(adj, bridge)
NNN = len(adj_new) - 1
cnt = [0] * (NNN + 1)
v_convert = {}
ii = 0
for v in idx_new[1:]:
ii += 1
cnt[v] += 1
v_convert[v] = ii
V_OK = []
for v in range(1, NNN + 1):
if cnt[v] == 1:
V_OK.append(v)
for v in V_OK:
v_ori = v_convert[v]
for u in adj[v_ori]:
vv = seq[v_ori - 1]
uu = seq[u - 1]
UF.unite(vv, uu)
#print(vv, uu)
#print("---")
for _ in range(Q):
x, y = map(int, input().split())
if not UF_ori.isSameGroup(x, y):
print("No")
continue
if UF.isSameGroup(x, y):
print("Yes")
else:
print("No")
if __name__ == '__main__':
main()
הההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההה
XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
0