結果

問題 No.1301 Strange Graph Shortest Path
ユーザー Kite_kumaKite_kuma
提出日時 2020-10-30 23:08:18
言語 PyPy3
(7.3.15)
結果
AC  
実行時間 2,048 ms / 3,000 ms
コード長 4,211 bytes
コンパイル時間 417 ms
コンパイル使用メモリ 82,396 KB
実行使用メモリ 299,976 KB
最終ジャッジ日時 2024-09-13 00:35:03
合計ジャッジ時間 55,078 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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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 41 ms
53,964 KB
testcase_01 AC 42 ms
54,484 KB
testcase_02 AC 1,706 ms
290,652 KB
testcase_03 AC 1,432 ms
270,472 KB
testcase_04 AC 1,940 ms
299,912 KB
testcase_05 AC 1,576 ms
290,912 KB
testcase_06 AC 1,912 ms
286,232 KB
testcase_07 AC 1,690 ms
286,616 KB
testcase_08 AC 1,499 ms
267,824 KB
testcase_09 AC 1,362 ms
270,312 KB
testcase_10 AC 1,345 ms
269,436 KB
testcase_11 AC 1,637 ms
291,036 KB
testcase_12 AC 1,641 ms
291,824 KB
testcase_13 AC 1,488 ms
291,552 KB
testcase_14 AC 1,819 ms
269,552 KB
testcase_15 AC 1,425 ms
270,164 KB
testcase_16 AC 2,026 ms
299,824 KB
testcase_17 AC 1,902 ms
294,876 KB
testcase_18 AC 1,800 ms
279,848 KB
testcase_19 AC 1,456 ms
287,764 KB
testcase_20 AC 1,669 ms
285,112 KB
testcase_21 AC 1,742 ms
292,312 KB
testcase_22 AC 1,804 ms
289,932 KB
testcase_23 AC 1,517 ms
291,624 KB
testcase_24 AC 1,840 ms
286,924 KB
testcase_25 AC 1,851 ms
298,496 KB
testcase_26 AC 1,706 ms
287,556 KB
testcase_27 AC 1,442 ms
290,140 KB
testcase_28 AC 1,565 ms
283,020 KB
testcase_29 AC 2,048 ms
299,976 KB
testcase_30 AC 1,535 ms
297,308 KB
testcase_31 AC 1,714 ms
297,212 KB
testcase_32 AC 43 ms
54,156 KB
testcase_33 AC 974 ms
293,816 KB
testcase_34 AC 1,525 ms
294,560 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

diff # 

import sys
import heapq


class mcf_graph:
    def __init__(self, n):
        self.n = n
        self.pos = []
        self.g = [[] for _ in range(n)]

    def add_edge(self, from_, to, cap, cost):
        assert 0 <= from_ < self.n
        assert 0 <= to < self.n
        m = len(self.pos)
        self.pos.append((from_, len(self.g[from_])))
        self.g[from_].append(self.__class__._edge(
            to, len(self.g[to]), cap, cost))
        self.g[to].append(self.__class__._edge(
            from_, len(self.g[from_]) - 1, 0, -cost))
        return m

    class edge:
        def __init__(self, from_, to, cap, flow, cost):
            self.from_ = from_
            self.to = to
            self.cap = cap
            self.flow = flow
            self.cost = cost

    def get_edge(self, i):
        _e = self.g[self.pos[i][0]][self.pos[i][1]]
        _re = self.g[_e.to][_e.rev]
        return self.__class__.edge(self.pos[i][0], _e.to, _e.cap + _re.cap, _re.cap, _e.cost)

    def edges(self):
        ret = []
        for i in range(len(self.pos)):
            _e = self.g[self.pos[i][0]][self.pos[i][1]]
            _re = self.g[_e.to][_e.rev]
            ret.append(self.__class__.edge(
                self.pos[i][0], _e.to, _e.cap + _re.cap, _re.cap, _e.cost))
        return ret

    def slope(self, s, t, flow_limit=float('inf')):
        # assert 0 <= s < self.n
        # assert 0 <= t < self.n
        # assert s != t

        dual = [0] * self.n
        dist = [float('inf')] * self.n
        pv = [-1] * self.n
        pe = [-1] * self.n

        def _dual_ref():
            nonlocal dual, dist, pv, pe
            dist = [float('inf')] * self.n
            pv = [-1] * self.n
            pe = [-1] * self.n

            que = [(0, s)]
            dist[s] = 0
            while que:
                dist_v, v = heapq.heappop(que)
                if dist[v] < dist_v:
                    continue
                if v == t:
                    break
                for i in range(len(self.g[v])):
                    e = self.g[v][i]
                    if e.cap == 0:
                        continue
                    cost = e.cost - dual[e.to] + dual[v]
                    if dist[e.to] > dist[v] + cost:
                        dist[e.to] = dist[v] + cost
                        pv[e.to] = v
                        pe[e.to] = i
                        heapq.heappush(que, (dist[e.to], e.to))
            if dist[t] == float('inf'):
                return False

            for v in range(self.n):
                if dist[v] == float('inf'):
                    continue
                dual[v] -= dist[t] - dist[v]

            return True

        flow = 0
        cost = 0
        prev_cost = -1
        result = [(flow, cost)]
        while flow < flow_limit:
            if not _dual_ref():
                break
            c = flow_limit - flow
            v = t
            while v != s:
                c = min(c, self.g[pv[v]][pe[v]].cap)
                v = pv[v]
            v = t
            while v != s:
                e = self.g[pv[v]][pe[v]]
                e.cap -= c
                self.g[v][e.rev].cap += c
                v = pv[v]
            d = -dual[s]
            flow += c
            cost += c * d
            if prev_cost == d:
                result.pop()
            result.append((flow, cost))
            prev_cost = cost
        return result

    def flow(self, s, t, flow_limit=float('inf')):
        return self.slope(s, t, flow_limit)[-1]

    class _edge:
        def __init__(self, to, rev, cap, cost):
            self.to = to
            self.rev = rev
            self.cap = cap
            self.cost = cost


input = sys.stdin.readline


n, m = map(int, input().split())
s, t = 0, n - 1
graph = mcf_graph(n + m)

for i in range(m):
    u, v, c, d = map(int, input().split())
    assert 1 <= u <= n and 1 <= v <= n and c <= d
    u -= 1
    v -= 1
    mid = n + i
    graph.add_edge(u, mid, 2, c)
    graph.add_edge(mid, v, 1, 0)
    graph.add_edge(mid, v, 1, d - c)
    graph.add_edge(v, mid, 2, c)
    graph.add_edge(mid, u, 1, 0)
    graph.add_edge(mid, u, 1, d - c)

flow, cost = graph.flow(s, t, 2)
assert flow == 2
print(cost)
0