#842358 (Python3) No.2286 Join Hands

提出ソース

結果

問題	No.2286 Join Hands
ユーザー	sapphire__15
提出日時	2023-02-22 02:29:34
言語	Python3 (3.12.2 + numpy 1.26.4 + scipy 1.12.0)
結果	AC
実行時間	235 ms / 2,000 ms
コード長	5,023 bytes
コンパイル時間	185 ms
コンパイル使用メモリ	13,056 KB
実行使用メモリ	18,304 KB
最終ジャッジ日時	2024-04-28 22:55:08
合計ジャッジ時間	8,189 ms
ジャッジサーバーID （参考情報）	judge5 / judge4

このコードへのチャレンジ
（要ログイン）

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	43 ms 11,776 KB
testcase_01	AC	41 ms 12,032 KB
testcase_02	AC	42 ms 11,776 KB
testcase_03	AC	42 ms 11,904 KB
testcase_04	AC	42 ms 11,776 KB
testcase_05	AC	42 ms 11,776 KB
testcase_06	AC	43 ms 11,904 KB
testcase_07	AC	43 ms 11,776 KB
testcase_08	AC	112 ms 15,488 KB
testcase_09	AC	119 ms 15,488 KB
testcase_10	AC	235 ms 16,640 KB
testcase_11	AC	204 ms 17,280 KB
testcase_12	AC	209 ms 17,408 KB
testcase_13	AC	232 ms 16,768 KB
testcase_14	AC	216 ms 17,664 KB
testcase_15	AC	213 ms 17,536 KB
testcase_16	AC	219 ms 17,792 KB
testcase_17	AC	112 ms 15,360 KB
testcase_18	AC	178 ms 17,536 KB
testcase_19	AC	112 ms 16,256 KB
testcase_20	AC	130 ms 16,640 KB
testcase_21	AC	182 ms 17,664 KB
testcase_22	AC	118 ms 16,512 KB
testcase_23	AC	100 ms 16,000 KB
testcase_24	AC	151 ms 17,280 KB
testcase_25	AC	105 ms 16,000 KB
testcase_26	AC	94 ms 16,000 KB
testcase_27	AC	98 ms 16,000 KB
testcase_28	AC	41 ms 11,904 KB
testcase_29	AC	42 ms 11,648 KB
testcase_30	AC	41 ms 11,904 KB
testcase_31	AC	42 ms 12,032 KB
testcase_32	AC	41 ms 11,776 KB
testcase_33	AC	43 ms 11,904 KB
testcase_34	AC	41 ms 11,776 KB
testcase_35	AC	42 ms 11,904 KB
testcase_36	AC	42 ms 11,776 KB
testcase_37	AC	43 ms 11,776 KB
testcase_38	AC	43 ms 11,776 KB
testcase_39	AC	41 ms 11,776 KB
testcase_40	AC	43 ms 11,776 KB
testcase_41	AC	41 ms 11,776 KB
testcase_42	AC	42 ms 12,032 KB
testcase_43	AC	43 ms 11,904 KB
testcase_44	AC	42 ms 11,904 KB
testcase_45	AC	42 ms 11,776 KB
testcase_46	AC	41 ms 11,904 KB
testcase_47	AC	123 ms 17,920 KB
testcase_48	AC	135 ms 18,304 KB
testcase_49	AC	123 ms 17,920 KB
testcase_50	AC	124 ms 18,304 KB
testcase_51	AC	65 ms 15,360 KB
testcase_52	AC	98 ms 16,128 KB
testcase_53	AC	135 ms 18,048 KB
testcase_54	AC	115 ms 16,640 KB
testcase_55	AC	123 ms 17,024 KB
testcase_56	AC	126 ms 18,176 KB
testcase_57	AC	123 ms 17,920 KB
testcase_58	AC	137 ms 18,176 KB
testcase_59	AC	124 ms 17,792 KB
testcase_60	AC	114 ms 17,920 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

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


def main():
    N, M = map(int, input().split())
    mf = MFGraph(N * 2 + 2)
    S, T = N * 2, N * 2 + 1
    cnt = [0] * N
    for _ in range(M):
        a, b = map(lambda x: int(x) - 1, input().split())
        cnt[a] += 1
        cnt[b] += 1
        mf.add_edge(a, b + N, 1)
        mf.add_edge(b, a + N, 1)
    
    for i in range(N):
        mf.add_edge(S, i, 1)
        mf.add_edge(i + N, T, 1)
    
    ans = mf.flow(S, T) * 2 - N

    if ans == N - 2 and min(cnt) == 0:
        ans -= 2
    
    print(ans)

if __name__ == '__main__':
    main()

yukicoder

結果

テストケース

ソースコード