#744348 (Python3) No.421 しろくろチョコレート

提出ソース

結果

問題	No.421 しろくろチョコレート
ユーザー	ygd.
提出日時	2022-03-08 21:50:03
言語	Python3 (3.12.2 + numpy 1.26.4 + scipy 1.12.0)
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

このコードへのチャレンジ
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テストケース

テストケース表示

入力	結果	実行時間実行使用メモリ
testcase_00	AC	42 ms 12,024 KB
testcase_01	AC	65 ms 13,688 KB
testcase_02	AC	49 ms 12,668 KB
testcase_03	AC	43 ms 11,904 KB
testcase_04	AC	48 ms 12,412 KB
testcase_05	AC	48 ms 12,412 KB
testcase_06	AC	43 ms 12,028 KB
testcase_07	AC	55 ms 12,920 KB
testcase_08	AC	49 ms 12,664 KB
testcase_09	AC	46 ms 12,032 KB
testcase_10	AC	45 ms 12,280 KB
testcase_11	AC	56 ms 13,048 KB
testcase_12	AC	41 ms 12,028 KB
testcase_13	AC	41 ms 11,768 KB
testcase_14	AC	43 ms 12,024 KB
testcase_15	AC	41 ms 11,900 KB
testcase_16	AC	76 ms 14,204 KB
testcase_17	AC	80 ms 14,328 KB
testcase_18	AC	88 ms 14,208 KB
testcase_19	AC	41 ms 11,900 KB
testcase_20	AC	68 ms 13,696 KB
testcase_21	AC	74 ms 13,944 KB
testcase_22	AC	57 ms 13,048 KB
testcase_23	AC	41 ms 11,904 KB
testcase_24	AC	40 ms 11,900 KB
testcase_25	AC	41 ms 11,896 KB
testcase_26	AC	41 ms 11,896 KB
testcase_27	AC	41 ms 11,900 KB
testcase_28	AC	58 ms 13,564 KB
testcase_29	AC	60 ms 13,820 KB
testcase_30	AC	60 ms 13,684 KB
testcase_31	AC	100 ms 15,220 KB
testcase_32	AC	60 ms 13,688 KB
testcase_33	AC	64 ms 13,820 KB
testcase_34	AC	47 ms 12,412 KB
testcase_35	AC	47 ms 12,664 KB
testcase_36	AC	58 ms 13,052 KB
testcase_37	AC	82 ms 14,076 KB
testcase_38	AC	92 ms 14,584 KB
testcase_39	AC	54 ms 12,920 KB
testcase_40	AC	63 ms 13,312 KB
testcase_41	AC	46 ms 12,280 KB
testcase_42	AC	46 ms 12,284 KB
testcase_43	AC	56 ms 13,180 KB
testcase_44	AC	76 ms 13,948 KB
testcase_45	AC	49 ms 12,408 KB
testcase_46	AC	47 ms 12,408 KB
testcase_47	AC	65 ms 13,308 KB
testcase_48	AC	89 ms 14,588 KB
testcase_49	AC	54 ms 12,920 KB
testcase_50	AC	48 ms 12,668 KB
testcase_51	AC	73 ms 13,944 KB
testcase_52	AC	57 ms 12,920 KB
testcase_53	AC	46 ms 12,416 KB
testcase_54	AC	49 ms 12,796 KB
testcase_55	AC	45 ms 12,152 KB
testcase_56	AC	45 ms 12,152 KB
testcase_57	AC	47 ms 12,288 KB
testcase_58	AC	63 ms 13,432 KB
testcase_59	AC	49 ms 12,540 KB
testcase_60	AC	103 ms 14,844 KB
testcase_61	AC	91 ms 14,844 KB
testcase_62	AC	42 ms 11,900 KB
testcase_63	AC	42 ms 12,028 KB
testcase_64	AC	43 ms 12,028 KB

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

raw source code

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 = 998244353
dx = [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+1
    wnum = 0; bnum = 0
    #隣接する白→黒
    for i in range(N):
        for j in range(M):
            if S[i][j] == '.': continue
            idx = i*M + j
            if S[i][j] == 'w':
                G.add_edge(source, idx, 1)
                wnum += 1
            if S[i][j] == 'b':
                G.add_edge(idx, terminal, 1)
                bnum += 1
            for d in range(4):
                ni = i + dx[d]
                nj = j + dy[d]
                nidx = ni * M + nj
                if ni < 0 or ni >= N or nj < 0 or nj >= M: continue
                if 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 -= tonari
    wnum -= tonari
    ans = 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, cast

class MFGraph:
    class Edge(NamedTuple):
        src: int
        dst: int
        cap: int
        flow: int
    class _Edge:
        def __init__(self, dst: int, cap: int) -> None:
            self.dst = dst
            self.cap = cap
            self.rev: Optional[MFGraph._Edge] = None
    def __init__(self, n: int) -> None:
        self._n = n
        self._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._n
        assert 0 <= dst < self._n
        assert 0 <= cap
        m = len(self._edges)
        e = MFGraph._Edge(dst, cap)
        re = MFGraph._Edge(src, 0)
        e.rev = re
        re.rev = e
        self._g[src].append(e)
        self._g[dst].append(re)
        self._edges.append(e)
        return m
    def 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_cap
        e = self._edges[i]
        e.cap = new_cap - new_flow
        assert e.rev is not None
        e.rev.cap = new_flow
    def flow(self, s: int, t: int, flow_limit: Optional[int] = None) -> int:
        assert 0 <= s < self._n
        assert 0 <= t < self._n
        assert s != t
        if flow_limit is None:
            flow_limit = cast(int, sum(e.cap for e in self._g[s]))
        current_edge = [0] * self._n
        level = [0] * self._n
        def fill(arr: List[int], value: int) -> None:
            for i in range(len(arr)):
                arr[i] = value
        def bfs() -> bool:
            fill(level, self._n)
            queue = []
            q_front = 0
            queue.append(s)
            level[s] = 0
            while q_front < len(queue):
                v = queue[q_front]
                q_front += 1
                next_level = level[v] + 1
                for e in self._g[v]:
                    if e.cap == 0 or level[e.dst] <= next_level:
                        continue
                    level[e.dst] = next_level
                    if e.dst == t:
                        return True
                    queue.append(e.dst)
            return False
        def 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 -= flow
                        assert e.rev is not None
                        e.rev.cap += flow
                    return flow
                next_level = level[v] - 1
                while 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] += 1
                        continue
                    stack.append(e.dst)
                    edge_stack.append(re)
                    break
                else:
                    stack.pop()
                    if edge_stack:
                        edge_stack.pop()
                    level[v] = self._n
            return 0
        flow = 0
        while flow < flow_limit:
            if not bfs():
                break
            fill(current_edge, 0)
            while flow < flow_limit:
                f = dfs(flow_limit - flow)
                flow += f
                if f == 0:
                    break
        return flow
    def min_cut(self, s: int) -> List[bool]:
        visited = [False] * self._n
        stack = [s]
        visited[s] = True
        while stack:
            v = stack.pop()
            for e in self._g[v]:
                if e.cap > 0 and not visited[e.dst]:
                    visited[e.dst] = True
                    stack.append(e.dst)
        return visited

################################################################################



if __name__ == '__main__':
    main()

yukicoder

結果

テストケース

ソースコード