結果
問題 | No.421 しろくろチョコレート |
ユーザー |
![]() |
提出日時 | 2022-03-08 21:50:03 |
言語 | Python3 (3.13.1 + numpy 2.2.1 + scipy 1.14.1) |
結果 |
AC
|
実行時間 | 103 ms / 2,000 ms |
コード長 | 6,474 bytes |
コンパイル時間 | 538 ms |
コンパイル使用メモリ | 13,184 KB |
実行使用メモリ | 15,220 KB |
最終ジャッジ日時 | 2024-07-23 21:40:57 |
合計ジャッジ時間 | 6,424 ms |
ジャッジサーバーID (参考情報) |
judge4 / judge2 |
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ファイルパターン | 結果 |
---|---|
other | AC * 65 |
ソースコード
import sys#input = sys.stdin.readline#input = sys.stdin.buffer.readline #文字列はダメ#sys.setrecursionlimit(1000000)#import bisect#import itertools#import random#from heapq import heapify, heappop, heappush#from collections import defaultdict#from collections import deque#import copy#import math#from functools import lru_cache#@lru_cache(maxsize=None)#MOD = pow(10,9) + 7#MOD = 998244353dx = [1,0,-1,0]dy = [0,1,0,-1]#隣接するものだけフローで求めればよい。#残った白と黒の個数からセットにするか、バラにするかは貪欲に選んでよい。def main():N,M = map(int,input().split())S = [str(input()) for _ in range(N)]G = MFGraph(N*M+2)source = N*M; terminal = N*M+1wnum = 0; bnum = 0#隣接する白→黒for i in range(N):for j in range(M):if S[i][j] == '.': continueidx = i*M + jif S[i][j] == 'w':G.add_edge(source, idx, 1)wnum += 1if S[i][j] == 'b':G.add_edge(idx, terminal, 1)bnum += 1for d in range(4):ni = i + dx[d]nj = j + dy[d]nidx = ni * M + njif ni < 0 or ni >= N or nj < 0 or nj >= M: continueif S[i][j] == 'w':G.add_edge(idx, nidx, 1)else:G.add_edge(nidx, idx, 1)tonari = G.flow(source, terminal)#print(tonari)bnum -= tonariwnum -= tonarians = tonari * 100 + min(bnum,wnum) * 10 + max(bnum,wnum) - min(bnum,wnum)print(ans)# Reference:# <https://github.com/not522/ac-library-python/blob/master/atcoder/maxflow.py># (commit hash: ed8c83d91c544bcfb600d3414899b8c01c268c9c)################################################################################from typing import NamedTuple, Optional, List, castclass MFGraph:class Edge(NamedTuple):src: intdst: intcap: intflow: intclass _Edge:def __init__(self, dst: int, cap: int) -> None:self.dst = dstself.cap = capself.rev: Optional[MFGraph._Edge] = Nonedef __init__(self, n: int) -> None:self._n = nself._g: List[List[MFGraph._Edge]] = [[] for _ in range(n)]self._edges: List[MFGraph._Edge] = []def add_edge(self, src: int, dst: int, cap: int) -> int:assert 0 <= src < self._nassert 0 <= dst < self._nassert 0 <= capm = len(self._edges)e = MFGraph._Edge(dst, cap)re = MFGraph._Edge(src, 0)e.rev = rere.rev = eself._g[src].append(e)self._g[dst].append(re)self._edges.append(e)return mdef get_edge(self, i: int) -> Edge:assert 0 <= i < len(self._edges)e = self._edges[i]re = cast(MFGraph._Edge, e.rev)return MFGraph.Edge(re.dst,e.dst,e.cap + re.cap,re.cap)def edges(self) -> List[Edge]:return [self.get_edge(i) for i in range(len(self._edges))]def change_edge(self, i: int, new_cap: int, new_flow: int) -> None:assert 0 <= i < len(self._edges)assert 0 <= new_flow <= new_cape = self._edges[i]e.cap = new_cap - new_flowassert e.rev is not Nonee.rev.cap = new_flowdef flow(self, s: int, t: int, flow_limit: Optional[int] = None) -> int:assert 0 <= s < self._nassert 0 <= t < self._nassert s != tif flow_limit is None:flow_limit = cast(int, sum(e.cap for e in self._g[s]))current_edge = [0] * self._nlevel = [0] * self._ndef fill(arr: List[int], value: int) -> None:for i in range(len(arr)):arr[i] = valuedef bfs() -> bool:fill(level, self._n)queue = []q_front = 0queue.append(s)level[s] = 0while q_front < len(queue):v = queue[q_front]q_front += 1next_level = level[v] + 1for e in self._g[v]:if e.cap == 0 or level[e.dst] <= next_level:continuelevel[e.dst] = next_levelif e.dst == t:return Truequeue.append(e.dst)return Falsedef dfs(lim: int) -> int:stack = []edge_stack: List[MFGraph._Edge] = []stack.append(t)while stack:v = stack[-1]if v == s:flow = min(lim, min(e.cap for e in edge_stack))for e in edge_stack:e.cap -= flowassert e.rev is not Nonee.rev.cap += flowreturn flownext_level = level[v] - 1while current_edge[v] < len(self._g[v]):e = self._g[v][current_edge[v]]re = cast(MFGraph._Edge, e.rev)if level[e.dst] != next_level or re.cap == 0:current_edge[v] += 1continuestack.append(e.dst)edge_stack.append(re)breakelse:stack.pop()if edge_stack:edge_stack.pop()level[v] = self._nreturn 0flow = 0while flow < flow_limit:if not bfs():breakfill(current_edge, 0)while flow < flow_limit:f = dfs(flow_limit - flow)flow += fif f == 0:breakreturn flowdef min_cut(self, s: int) -> List[bool]:visited = [False] * self._nstack = [s]visited[s] = Truewhile stack:v = stack.pop()for e in self._g[v]:if e.cap > 0 and not visited[e.dst]:visited[e.dst] = Truestack.append(e.dst)return visited################################################################################if __name__ == '__main__':main()