結果
問題 | No.1718 Random Squirrel |
ユーザー |
|
提出日時 | 2023-03-26 20:47:11 |
言語 | Python3 (3.13.1 + numpy 2.2.1 + scipy 1.14.1) |
結果 |
AC
|
実行時間 | 1,549 ms / 2,000 ms |
コード長 | 3,583 bytes |
コンパイル時間 | 81 ms |
コンパイル使用メモリ | 13,056 KB |
実行使用メモリ | 94,308 KB |
最終ジャッジ日時 | 2024-09-19 10:00:00 |
合計ジャッジ時間 | 23,544 ms |
ジャッジサーバーID (参考情報) |
judge5 / judge4 |
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ファイルパターン | 結果 |
---|---|
sample | AC * 2 |
other | AC * 31 |
ソースコード
from collections import defaultdictfrom typing import List, TupleINF = int(1e18)def randomSquirrel(n: int, edges: List[Tuple[int, int]], sweets: List[int]) -> List[int]:E = Tuple[int, int] # (maxDist, mustVisitCount)def e(root: int) -> E:return (0, 0) if isSpecial[root] else (-INF, 0)def op(childRes1: E, childRes2: E) -> E:dist1, must1 = childRes1dist2, must2 = childRes2return (max(dist1, dist2), must1 + must2)def composition(fromRes: E, parent: int, cur: int, direction: int) -> E:"""direction: 0: cur -> parent, 1: parent -> cur"""dist, must = fromResw = weights[cur][parent] if direction == 0 else weights[parent][cur]# dist>=0 才开始算入必须经过的路径return (dist + w, must + 1) if dist >= 0 else (dist, must)isSpecial = [False] * nfor v in sweets:isSpecial[v] = TrueR = Rerooting(n)weights = [defaultdict(int) for _ in range(n)]for u, v in edges:R.addEdge(u, v)weights[u][v] = 1weights[v][u] = 1dp = R.rerooting(e=e, op=op, composition=composition, root=0)res = [mustVisit * 2 - maxDist for maxDist, mustVisit in dp] # 可以不回到出发点,2*点数-最大距离return resfrom typing import Callable, Generic, List, TypeVarT = TypeVar("T")class Rerooting(Generic[T]):__slots__ = ("adjList", "_n", "_decrement")def __init__(self, n: int, decrement: int = 0):self.adjList = [[] for _ in range(n)]self._n = nself._decrement = decrementdef addEdge(self, u: int, v: int) -> None:u -= self._decrementv -= self._decrementself.adjList[u].append(v)self.adjList[v].append(u)def rerooting(self,e: Callable[[int], T],op: Callable[[T, T], T],composition: Callable[[T, int, int, int], T],root=0,) -> List["T"]:root -= self._decrementassert 0 <= root < self._nparents = [-1] * self._norder = [root]stack = [root]while stack:cur = stack.pop()for next in self.adjList[cur]:if next == parents[cur]:continueparents[next] = curorder.append(next)stack.append(next)dp1 = [e(i) for i in range(self._n)]dp2 = [e(i) for i in range(self._n)]for cur in order[::-1]:res = e(cur)for next in self.adjList[cur]:if parents[cur] == next:continuedp2[next] = resres = op(res, composition(dp1[next], cur, next, 0))res = e(cur)for next in self.adjList[cur][::-1]:if parents[cur] == next:continuedp2[next] = op(res, dp2[next])res = op(res, composition(dp1[next], cur, next, 0))dp1[cur] = resfor newRoot in order[1:]:parent = parents[newRoot]dp2[newRoot] = composition(op(dp2[newRoot], dp2[parent]), parent, newRoot, 1)dp1[newRoot] = op(dp1[newRoot], dp2[newRoot])return dp1if __name__ == "__main__":n, k = map(int, input().split())edges = []for _ in range(n - 1):u, v = map(int, input().split())u, v = u - 1, v - 1edges.append((u, v))sweets = [int(x) - 1 for x in input().split()]print(*randomSquirrel(n, edges, sweets), sep="\n")