結果

問題 No.1295 木と駒
ユーザー Kiri8128
提出日時 2020-11-23 16:23:53
言語 PyPy3
(7.3.15)
結果
AC  
実行時間 417 ms / 2,000 ms
コード長 2,398 bytes
コンパイル時間 416 ms
コンパイル使用メモリ 82,304 KB
実行使用メモリ 114,760 KB
最終ジャッジ日時 2024-07-23 17:34:15
合計ジャッジ時間 13,983 ms
ジャッジサーバーID
(参考情報)
judge5 / judge2
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 * 1
other AC * 48
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 collections import deque
N = int(input())
X = [[] for i in range(N)]
for i in range(N-1):
x, y = map(int, input().split())
x, y = x-1, y-1
X[x].append(y)
X[y].append(x)
MI = [min(x) for x in X]
MA = [max(x) for x in X]
MA2 = [max([y for y in x + [-1] if y != ma]) for x, ma in zip(X, MA)]
if False:
print("MI =", MI)
print("MA =", MA)
print("MA2 =", MA2)
P = [-1] * N
Q = deque([0])
R = []
while Q:
i = deque.popleft(Q)
R.append(i)
for a in X[i]:
if a != P[i]:
P[a] = i
X[a].remove(i)
deque.append(Q, a)
##### Settings
unit = 0
merge = lambda a, b: a + b
## ↓ 2
adj_bu = lambda a, i: a * inv(SIZE[i]) % mod
adj_td = lambda a, i, p: a * inv(N-SIZE[i]) % mod # SIZEip使
def adj_bu(a, i, p):
if a >= 4: return 4
if a == 0 and p == MI[i]: return 0
if a == 3 and p != MA[i]: return 4
if i == MA[p] or i == MI[p]: return 2
if i == MA2[p]: return 3
return 4
def adj_td(a, i, p):
return adj_bu(a, p, i)
adj_fin = lambda a, i: "Yes" if a <= 2 else "No"
#####
if False:
nn = 200200
fa = [1] * (nn+1)
fainv = [1] * (nn+1)
for i in range(nn):
fa[i+1] = fa[i] * (i+1) % mod
fainv[-1] = pow(fa[-1], mod-2, mod)
for i in range(nn)[::-1]:
fainv[i] = fainv[i+1] * (i+1) % mod
inv = lambda i: fainv[i] * fa[i-1] % mod
print("fa =", fa[:20])
print("fainv =", fainv[:20])
if False:
SIZE = [1] * N
for i in R[1:][::-1]:
SIZE[P[i]] += SIZE[i]
print("SIZE =", SIZE) # Size of subtree
ME = [unit] * N
XX = [0] * N
TD = [unit] * N
for i in R[1:][::-1]:
p = P[i]
XX[i] = adj_bu(ME[i], i, p) ####################
ME[p] = merge(ME[p], XX[i])
XX[R[0]] = adj_fin(ME[R[0]], R[0])
if False:
print("ME =", ME) # Merge before adj
print("XX =", XX) # Bottom-up after adj
for i in R:
ac = TD[i]
for j in X[i]:
TD[j] = ac
ac = merge(ac, XX[j])
ac = unit
for j in X[i][::-1]:
TD[j] = adj_td(merge(TD[j], ac), j, i)
ac = merge(ac, XX[j])
XX[j] = adj_fin(merge(ME[j], TD[j]), j)
if False:
print("TD =", TD) # Top-down after adj
print("XX =", XX) # Final Result
print("\n".join(XX))
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