結果
問題 | No.778 クリスマスツリー |
ユーザー |
|
提出日時 | 2023-10-30 00:13:16 |
言語 | PyPy3 (7.3.15) |
結果 |
AC
|
実行時間 | 1,294 ms / 2,000 ms |
コード長 | 4,614 bytes |
コンパイル時間 | 450 ms |
コンパイル使用メモリ | 81,872 KB |
実行使用メモリ | 412,256 KB |
最終ジャッジ日時 | 2024-09-25 17:00:14 |
合計ジャッジ時間 | 10,060 ms |
ジャッジサーバーID (参考情報) |
judge1 / judge2 |
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ファイルパターン | 結果 |
---|---|
sample | AC * 3 |
other | AC * 12 |
ソースコード
# https://github.com/tatyam-prime/SortedSet/blob/main/SortedMultiset.pyimport mathfrom bisect import bisect_left, bisect_right, insortfrom typing import Generic, Iterable, Iterator, TypeVar, Union, ListT = TypeVar('T')class SortedMultiset(Generic[T]):BUCKET_RATIO = 50REBUILD_RATIO = 170def _build(self, a=None) -> None:"Evenly divide `a` into buckets."if a is None: a = list(self)size = self.size = len(a)bucket_size = int(math.ceil(math.sqrt(size / self.BUCKET_RATIO)))self.a = [a[size * i // bucket_size : size * (i + 1) // bucket_size] for i in range(bucket_size)]def __init__(self, a: Iterable[T] = []) -> None:"Make a new SortedMultiset from iterable. / O(N) if sorted / O(N log N)"a = list(a)if not all(a[i] <= a[i + 1] for i in range(len(a) - 1)):a = sorted(a)self._build(a)def __iter__(self) -> Iterator[T]:for i in self.a:for j in i: yield jdef __reversed__(self) -> Iterator[T]:for i in reversed(self.a):for j in reversed(i): yield jdef __len__(self) -> int:return self.sizedef __repr__(self) -> str:return "SortedMultiset" + str(self.a)def __str__(self) -> str:s = str(list(self))return "{" + s[1 : len(s) - 1] + "}"def _find_bucket(self, x: T) -> List[T]:"Find the bucket which should contain x. self must not be empty."for a in self.a:if x <= a[-1]: return areturn adef __contains__(self, x: T) -> bool:if self.size == 0: return Falsea = self._find_bucket(x)i = bisect_left(a, x)return i != len(a) and a[i] == xdef 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 = 1returna = self._find_bucket(x)insort(a, x)self.size += 1if len(a) > len(self.a) * self.REBUILD_RATIO:self._build()def discard(self, x: T) -> bool:"Remove an element and return True if removed. / O(√N)"if self.size == 0: return Falsea = self._find_bucket(x)i = bisect_left(a, x)if i == len(a) or a[i] != x: return Falsea.pop(i)self.size -= 1if len(a) == 0: self._build()return Truedef lt(self, x: T) -> Union[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) -> Union[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) -> Union[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) -> Union[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, x: int) -> T:"Return the x-th element, or IndexError if it doesn't exist."if x < 0: x += self.sizeif x < 0: raise IndexErrorfor a in self.a:if x < len(a): return a[x]x -= len(a)raise IndexErrordef index(self, x: T) -> int:"Count the number of elements < x."ans = 0for a in self.a:if a[-1] >= x:return ans + bisect_left(a, x)ans += len(a)return ansdef index_right(self, x: T) -> int:"Count the number of elements <= x."ans = 0for a in self.a:if a[-1] > x:return ans + bisect_right(a, x)ans += len(a)return ansfrom collections import defaultdictimport syssys.setrecursionlimit(10**6)n = int(input())A = list(map(int, input().split()))G = defaultdict(list)for i in range(n - 1):p = A[i]G[p].append(i + 1)ans = 0seen = SortedMultiset()def rec(ci):global ansans += seen.index(ci)seen.add(ci)for np in G[ci]:rec(np)seen.discard(ci)rec(0)print(ans)