結果
問題 |
No.3206 う し た ウ ニ 木 あ く ん 笑
|
ユーザー |
![]() |
提出日時 | 2025-07-18 22:30:46 |
言語 | PyPy3 (7.3.15) |
結果 |
AC
|
実行時間 | 1,410 ms / 3,000 ms |
コード長 | 6,765 bytes |
コンパイル時間 | 345 ms |
コンパイル使用メモリ | 82,708 KB |
実行使用メモリ | 204,892 KB |
最終ジャッジ日時 | 2025-07-18 22:31:08 |
合計ジャッジ時間 | 20,886 ms |
ジャッジサーバーID (参考情報) |
judge2 / judge1 |
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ファイルパターン | 結果 |
---|---|
sample | AC * 2 |
other | AC * 30 |
ソースコード
# https://github.com/tatyam-prime/SortedSet/blob/main/SortedMultiset.py import math from bisect import bisect_left, bisect_right from typing import Generic, Iterable, Iterator, TypeVar T = TypeVar('T') class SortedMultiset(Generic[T]): BUCKET_RATIO = 16 SPLIT_RATIO = 24 def __init__(self, a: Iterable[T] = []) -> None: "Make a new SortedMultiset from iterable. / O(N) if sorted / O(N log N)" a = list(a) n = self.size = len(a) if any(a[i] > a[i + 1] for i in range(n - 1)): a.sort() num_bucket = int(math.ceil(math.sqrt(n / self.BUCKET_RATIO))) self.a = [a[n * i // num_bucket : n * (i + 1) // num_bucket] for i in range(num_bucket)] def __iter__(self) -> Iterator[T]: for i in self.a: for j in i: yield j def __reversed__(self) -> Iterator[T]: for i in reversed(self.a): for j in reversed(i): yield j def __eq__(self, other) -> bool: return list(self) == list(other) def __len__(self) -> int: return self.size def __repr__(self) -> str: return "SortedMultiset" + str(self.a) def __str__(self) -> str: s = str(list(self)) return "{" + s[1 : len(s) - 1] + "}" def _position(self, x: T) -> tuple[list[T], int, int]: "return the bucket, index of the bucket and position in which x should be. self must not be empty." for i, a in enumerate(self.a): if x <= a[-1]: break return (a, i, bisect_left(a, x)) def __contains__(self, x: T) -> bool: if self.size == 0: return False a, _, i = self._position(x) return i != len(a) and a[i] == x def count(self, x: T) -> int: "Count the number of x." return self.index_right(x) - self.index(x) def add(self, x: T) -> None: "Add an element. / O(√N)" if self.size == 0: self.a = [[x]] self.size = 1 return a, b, i = self._position(x) a.insert(i, x) self.size += 1 if len(a) > len(self.a) * self.SPLIT_RATIO: mid = len(a) >> 1 self.a[b:b+1] = [a[:mid], a[mid:]] def _pop(self, a: list[T], b: int, i: int) -> T: ans = a.pop(i) self.size -= 1 if not a: del self.a[b] return ans def discard(self, x: T) -> bool: "Remove an element and return True if removed. / O(√N)" if self.size == 0: return False a, b, i = self._position(x) if i == len(a) or a[i] != x: return False self._pop(a, b, i) return True def lt(self, x: T) -> T | None: "Find the largest element < x, or None if it doesn't exist." for a in reversed(self.a): if a[0] < x: return a[bisect_left(a, x) - 1] def le(self, x: T) -> T | None: "Find the largest element <= x, or None if it doesn't exist." for a in reversed(self.a): if a[0] <= x: return a[bisect_right(a, x) - 1] def gt(self, x: T) -> T | None: "Find the smallest element > x, or None if it doesn't exist." for a in self.a: if a[-1] > x: return a[bisect_right(a, x)] def ge(self, x: T) -> T | None: "Find the smallest element >= x, or None if it doesn't exist." for a in self.a: if a[-1] >= x: return a[bisect_left(a, x)] def __getitem__(self, i: int) -> T: "Return the i-th element." if i < 0: for a in reversed(self.a): i += len(a) if i >= 0: return a[i] else: for a in self.a: if i < len(a): return a[i] i -= len(a) raise IndexError def pop(self, i: int = -1) -> T: "Pop and return the i-th element." if i < 0: for b, a in enumerate(reversed(self.a)): i += len(a) if i >= 0: return self._pop(a, ~b, i) else: for b, a in enumerate(self.a): if i < len(a): return self._pop(a, b, i) i -= len(a) raise IndexError def index(self, x: T) -> int: "Count the number of elements < x." ans = 0 for a in self.a: if a[-1] >= x: return ans + bisect_left(a, x) ans += len(a) return ans def index_right(self, x: T) -> int: "Count the number of elements <= x." ans = 0 for a in self.a: if a[-1] > x: return ans + bisect_right(a, x) ans += len(a) return ans N = int(input()) Graph = [[] for _ in range(N)] for _ in range(N - 1): a, b = map(int, input().split()) a -= 1 b -= 1 Graph[a].append(b) Graph[b].append(a) done = [0] * N Q = [~0, 0] # 根をスタックに追加 ET = [] dp = [0] * N L = [SortedMultiset([]) for _ in range(N)] Parent = [-1 for _ in range(N)] Children = [[] for _ in range(N)] while Q: i = Q.pop() if i >= 0: # 行きがけの処理 done[i] = 1 ET.append(i) for a in Graph[i][::-1]: if done[a]: continue Parent[a] = i Children[i].append(a) Q.append(~a) # 帰りがけの処理をスタックに追加 Q.append(a) # 行きがけの処理をスタックに追加 else: # 帰りがけの処理 i = ~i ET.append(i) for x in Children[i]: L[i].add(dp[x]) if(len(L[i]) > 0): dp[i] = L[i][-1] + 1 else: dp[i] = 1 # if(len(L[i]) >= 3): # dp[i] = L[i][-1] + L[i][-2] + L[i][-3] + 1 # else: # dp[i] = 0 # print(ET) # print(L) # print(dp) Seen = [False] * N s = 0 ans = 0 # for x in Graph[0]: # ans = max(ans, dp[x]) for i in range(len(L[0])): ans = max(ans, L[0][i] * (len(L[0]) - i) + 1) # print(ans) for i in range(1, len(ET) - 1): x = ET[i] if(not Seen[x]): #pre -> x Seen[x] = True t = x else: #x -> Parent[x] t = Parent[x] #(sからtに交換) L[s].discard(dp[t]) # if(len(L[s]) >= 3): # dp[s] = L[s][-1] + L[s][-2] + L[s][-3] + 1 # else: # dp[s] = 0 if(len(L[s]) > 0): dp[s] = L[s][-1] + 1 else: dp[s] = 1 L[t].add(dp[s]) if(len(L[t]) > 0): dp[t] = L[t][-1] + 1 else: dp[t] = 1 # print(s, t) # print(L) # print(dp) # print(L[t]) # print() for i in range(len(L[t])): ans = max(ans, L[t][i] * (len(L[t]) - i) + 1) s = t if(ans == 0): print(-1) else: print(ans) # print(ans)