結果

問題 No.2523 Trick Flower
ユーザー MasKoaTS
提出日時 2023-03-31 20:07:22
言語 PyPy3
(7.3.15)
結果
AC  
実行時間 871 ms / 4,000 ms
コード長 2,460 bytes
コンパイル時間 320 ms
コンパイル使用メモリ 82,276 KB
実行使用メモリ 262,496 KB
最終ジャッジ日時 2024-09-25 05:55:30
合計ジャッジ時間 13,332 ms
ジャッジサーバーID
（参考情報） 		judge2 / judge1
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 * 3
other AC * 31
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 # 

import sys
input = sys.stdin.readline

class SCC:
	def __init__(self, n):
		self.n = n
		self.graph = [[] for _ in range(n)]
		self.rev_graph = [[] for _ in range(n)]
		self.labels = [-1] * n
		self.lb_cnt = 0
	
	def add_edge(self, v, nxt_v):
		self.graph[v].append(nxt_v)
		self.rev_graph[nxt_v].append(v)

	def build(self):
		self.post_order = []
		self.used = [False] * self.n
		for v in range(self.n):
			if(self.used[v]):
				continue
			self._dfs(v)
		for v in reversed(self.post_order):
			if(self.labels[v] != -1):
				continue
			self._rev_dfs(v)
			self.lb_cnt += 1

	def _dfs(self, v):
		stack = [v, 0]
		while(stack):
			v, idx = stack[-2:]
			if(not(idx) and self.used[v]):
				stack.pop()
				stack.pop()
			else:
				self.used[v] = True
				if(idx < len(self.graph[v])):
					stack[-1] += 1
					stack.append(self.graph[v][idx])
					stack.append(0)
				else:
					stack.pop()
					self.post_order.append(stack.pop())

	def _rev_dfs(self, v):
		stack = [v]
		self.labels[v] = self.lb_cnt
		while stack:
			v = stack.pop()
			for nxt_v in self.rev_graph[v]:
				if(self.labels[nxt_v] != -1):
					continue
				stack.append(nxt_v)
				self.labels[nxt_v] = self.lb_cnt

	def construct(self):
		self.dag = [[] for i in range(self.lb_cnt)]
		self.groups = [[] for i in range(self.lb_cnt)]
		for v, lb in enumerate(self.labels):
			for nxt_v in self.graph[v]:
				nxt_lb = self.labels[nxt_v]
				if(lb == nxt_lb):
					continue
				self.dag[lb].append(nxt_lb)
			self.groups[lb].append(v)
		return self.dag, self.groups


"""
Main Code
"""

N = int(input())
A = list(map(int, input().split()))
B = list(map(int, input().split()))
c = list(map(int, input().split()))

scc = SCC(N)
for i, k in enumerate(c):
	if(i == k - 1):
		continue
	scc.add_edge(k - 1, i)
scc.build()
dag, groups = scc.construct()

n = len(groups)
a = [0] * n
b = [0] * n
for i, g in enumerate(groups):
	a[i] = sum(A[k] for k in g)
	b[i] = sum(B[k] for k in g)

rdag = [[] for _ in [0] * n]
for i, lis in enumerate(dag):
	for v in lis:
		rdag[v].append(i)

def check(mid):
	visited = set([])
	dp = [aa - mid * bb for aa, bb in zip(a, b)]
	for x in range(n - 1, -1, -1):
		if(x in visited):
			continue
		visited.add(x)
		if(dp[x] > 0):
			dp[x] = 0
		if(not(rdag[x]) and dp[x] < 0):
			return False
		for y in rdag[x]:
			dp[y] += dp[x]
	return True

ok = 0
ng = sum(a) // sum(b) + 1
while(ng - ok > 1):
	mid = (ok + ng) >> 1
	if(check(mid)):
		ok = mid
	else:
		ng = mid
print(ok)
0