結果

問題 No.1301 Strange Graph Shortest Path
ユーザー Kite_kumaKite_kuma
提出日時 2020-10-30 22:55:53
言語 PyPy3
(7.3.15)
結果
AC  
実行時間 1,730 ms / 3,000 ms
コード長 3,514 bytes
コンパイル時間 355 ms
コンパイル使用メモリ 82,292 KB
実行使用メモリ 279,660 KB
最終ジャッジ日時 2024-09-13 00:30:51
合計ジャッジ時間 45,978 ms
ジャッジサーバーID
（参考情報） 		judge5 / judge1
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 38 ms
54,452 KB
testcase_01 AC 38 ms
53,824 KB
testcase_02 AC 1,406 ms
267,148 KB
testcase_03 AC 1,062 ms
247,492 KB
testcase_04 AC 1,706 ms
274,872 KB
testcase_05 AC 1,418 ms
268,396 KB
testcase_06 AC 1,609 ms
268,928 KB
testcase_07 AC 1,465 ms
269,208 KB
testcase_08 AC 1,175 ms
251,880 KB
testcase_09 AC 1,021 ms
252,824 KB
testcase_10 AC 999 ms
248,624 KB
testcase_11 AC 1,414 ms
272,080 KB
testcase_12 AC 1,369 ms
273,408 KB
testcase_13 AC 1,230 ms
267,124 KB
testcase_14 AC 1,499 ms
253,644 KB
testcase_15 AC 1,038 ms
253,072 KB
testcase_16 AC 1,609 ms
275,084 KB
testcase_17 AC 1,546 ms
270,900 KB
testcase_18 AC 1,352 ms
262,364 KB
testcase_19 AC 1,181 ms
268,168 KB
testcase_20 AC 1,387 ms
266,508 KB
testcase_21 AC 1,507 ms
267,576 KB
testcase_22 AC 1,583 ms
272,060 KB
testcase_23 AC 1,264 ms
267,404 KB
testcase_24 AC 1,543 ms
268,608 KB
testcase_25 AC 1,531 ms
274,228 KB
testcase_26 AC 1,449 ms
269,116 KB
testcase_27 AC 1,256 ms
270,928 KB
testcase_28 AC 1,253 ms
267,212 KB
testcase_29 AC 1,730 ms
274,608 KB
testcase_30 AC 1,316 ms
272,292 KB
testcase_31 AC 1,481 ms
271,968 KB
testcase_32 AC 38 ms
53,932 KB
testcase_33 AC 850 ms
267,096 KB
testcase_34 AC 1,438 ms
279,660 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 # 

from heapq import heappop, heappush, heapify
import sys
input = sys.stdin.readline


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

    def add_edge(self, fr, to, cap, cost):
        m = len(self.pos)
        self.pos.append((fr, len(self.graph[fr])))
        self.graph[fr].append([to, len(self.graph[to]), cap, cost])
        self.graph[to].append([fr, len(self.graph[fr]) - 1, 0, -cost])
        return m

    def get_edge(self, idx):
        to, rev, cap, cost = self.graph[self.pos[idx][0]][self.pos[idx][1]]
        rev_to, rev_rev, rev_cap, rev_cost = self.graph[to][rev]
        return self.pos[idx][0], to, cap + rev_cap, rev_cap, cost

    def edges(self):
        for i in range(len(self.pos)):
            yield self.get_edge(i)

    def dual_ref(self, s, t):
        dist = [2**63 - 1] * self.n
        dist[s] = 0
        vis = [0] * self.n
        self.pv = [-1] * self.n
        self.pe = [-1] * self.n
        queue = []
        heappush(queue, (0, s))
        while queue:
            k, v = heappop(queue)
            if vis[v]:
                continue
            vis[v] = True
            if v == t:
                break
            for i in range(len(self.graph[v])):
                to, rev, cap, cost = self.graph[v][i]
                if vis[to] or cap == 0:
                    continue
                cost += self.dual[v] - self.dual[to]
                if dist[to] - dist[v] > cost:
                    dist[to] = dist[v] + cost
                    self.pv[to] = v
                    self.pe[to] = i
                    heappush(queue, (dist[to], to))
        if not vis[t]:
            return False
        for v in range(self.n):
            if not vis[v]:
                continue
            self.dual[v] -= dist[t] - dist[v]
        return True

    def flow(self, s, t): return self.flow_with_limit(s, t, 2**63 - 1)
    def flow_with_limit(
        self, s, t, limit): return self.slope_with_limit(s, t, limit)[-1]

    def slope(self, s, t): return self.slope_with_limit(s, t, 2**63 - 1)

    def slope_with_limit(self, s, t, limit):
        flow = 0
        cost = 0
        prev_cost = -1
        res = [(flow, cost)]
        self.dual = [0] * self.n
        while flow < limit:
            if not self.dual_ref(s, t):
                break
            c = limit - flow
            v = t
            while v != s:
                c = min(c, self.graph[self.pv[v]][self.pe[v]][2])
                v = self.pv[v]
            v = t
            while v != s:
                to, rev, cap, _ = self.graph[self.pv[v]][self.pe[v]]
                self.graph[self.pv[v]][self.pe[v]][2] -= c
                self.graph[v][rev][2] += c
                v = self.pv[v]
            d = -self.dual[s]
            flow += c
            cost += c * d
            if prev_cost == d:
                res.pop()
            res.append((flow, cost))
            prev_cost = cost
        return res


n, m = map(int, input().split())
s, t = 0, n - 1
graph = MinCostFlow(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_with_limit(s, t, 2)
assert flow == 2
print(cost)
0