結果
| 問題 |
No.3129 Multiple of Twin Subarray
|
| ユーザー |
 detteiuu
|
| 提出日時 | 2025-04-25 22:07:21 |
| 言語 | PyPy3 (7.3.15) |
| 結果 |
AC
|
| 実行時間 | 1,437 ms / 2,000 ms |
| コード長 | 5,886 bytes |
| コンパイル時間 | 475 ms |
| コンパイル使用メモリ | 82,648 KB |
| 実行使用メモリ | 160,744 KB |
| 最終ジャッジ日時 | 2025-04-25 22:08:01 |
| 合計ジャッジ時間 | 31,246 ms |
|
ジャッジサーバーID （参考情報） |
judge3 / judge5 |
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| ファイルパターン | 結果 |
|---|---|
| sample | AC * 3 |
| other | AC * 46 |
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, List, Tuple, TypeVar, Optional
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) -> Optional[T]:
"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) -> Optional[T]:
"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) -> Optional[T]:
"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) -> Optional[T]:
"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())
A = list(map(int, input().split()))
INF = 1<<60
def func(A):
cum = [0]
for a in A:
cum.append(cum[-1]+a)
L = [[-INF, INF, INF, INF] for _ in range(N)]
S = SortedMultiset([0])
for i in range(1, N+1):
L[i-1][0] = cum[i]-S[0]
L[i-1][1] = cum[i]-S[-1]
b = S.index(cum[i])
if b < len(S) and S[b] == cum[i]:
L[i-1][2] = 0
L[i-1][3] = 0
else:
if 1 <= b:
L[i-1][2] = cum[i]-S[b-1]
if b < len(S):
L[i-1][3] = cum[i]-S[b]
if 2 <= i:
L[i-1][0] = max(L[i-1][0], L[i-2][0])
L[i-1][1] = min(L[i-1][1], L[i-2][1])
L[i-1][2] = min(L[i-1][2], L[i-2][2])
L[i-1][3] = max(L[i-1][3], L[i-2][3])
S.add(cum[i])
return L
L = func(A)
R = func(A[::-1])[::-1]
ans = -INF
for i in range(N-1):
ans = max(ans, L[i][0]*R[i+1][0], L[i][1]*R[i+1][1])
if L[i][2] != INF and R[i+1][3] != INF:
ans = max(ans, L[i][2]*R[i+1][3])
if L[i][3] != INF and R[i+1][2] != INF:
ans = max(ans, L[i][3]*R[i+1][2])
print(ans)