結果

問題 No.1301 Strange Graph Shortest Path
ユーザー eijiroueijirou
提出日時 2020-11-28 10:15:45
言語 PyPy3
(7.3.15)
結果
AC  
実行時間 1,175 ms / 3,000 ms
コード長 2,014 bytes
コンパイル時間 460 ms
コンパイル使用メモリ 86,480 KB
実行使用メモリ 212,832 KB
最終ジャッジ日時 2023-10-09 23:41:34
合計ジャッジ時間 35,965 ms
ジャッジサーバーID
（参考情報） 		judge11 / judge12
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 66 ms
70,776 KB
testcase_01 AC 66 ms
70,972 KB
testcase_02 AC 1,009 ms
198,956 KB
testcase_03 AC 922 ms
184,672 KB
testcase_04 AC 1,062 ms
203,208 KB
testcase_05 AC 962 ms
201,492 KB
testcase_06 AC 994 ms
193,924 KB
testcase_07 AC 956 ms
195,776 KB
testcase_08 AC 945 ms
186,932 KB
testcase_09 AC 933 ms
187,056 KB
testcase_10 AC 928 ms
186,136 KB
testcase_11 AC 1,175 ms
197,728 KB
testcase_12 AC 1,062 ms
197,580 KB
testcase_13 AC 999 ms
200,464 KB
testcase_14 AC 935 ms
187,796 KB
testcase_15 AC 965 ms
188,876 KB
testcase_16 AC 1,045 ms
203,700 KB
testcase_17 AC 1,060 ms
202,108 KB
testcase_18 AC 1,088 ms
191,764 KB
testcase_19 AC 1,011 ms
195,568 KB
testcase_20 AC 951 ms
191,124 KB
testcase_21 AC 986 ms
199,308 KB
testcase_22 AC 1,086 ms
194,828 KB
testcase_23 AC 1,042 ms
200,132 KB
testcase_24 AC 972 ms
192,736 KB
testcase_25 AC 1,075 ms
203,088 KB
testcase_26 AC 1,035 ms
194,684 KB
testcase_27 AC 1,052 ms
197,764 KB
testcase_28 AC 881 ms
195,496 KB
testcase_29 AC 1,040 ms
201,992 KB
testcase_30 AC 1,116 ms
202,716 KB
testcase_31 AC 1,081 ms
202,048 KB
testcase_32 AC 70 ms
70,932 KB
testcase_33 AC 510 ms
195,692 KB
testcase_34 AC 1,168 ms
212,832 KB
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ソースコード

diff # 

# Reference: https://tjkendev.github.io/procon-library/python/min_cost_flow/primal-dual.html
from heapq import heappush, heappop
class MinCostFlow:
    INF = 10**18

    def __init__(self, N):
        self.N = N
        self.G = [[] for i in range(N)]

    def add_edge(self, fr, to, cap, cost):
        forward = [to, cap, cost, None]
        backward = forward[3] = [fr, 0, -cost, forward]
        self.G[fr].append(forward)
        self.G[to].append(backward)

    def flow(self, s, t, f):
        N = self.N; G = self.G
        INF = MinCostFlow.INF

        res = 0
        H = [0]*N
        prv_v = [0]*N
        prv_e = [None]*N

        d0 = [INF]*N
        dist = [INF]*N

        while f:
            dist[:] = d0
            dist[s] = 0
            que = [(0, s)]

            while que:
                c, v = heappop(que)
                if dist[v] < c:
                    continue
                r0 = dist[v] + H[v]
                for e in G[v]:
                    w, cap, cost, _ = e
                    if cap > 0 and r0 + cost - H[w] < dist[w]:
                        dist[w] = r = r0 + cost - H[w]
                        prv_v[w] = v; prv_e[w] = e
                        heappush(que, (r, w))
            if dist[t] == INF:
                return None

            for i in range(N):
                H[i] += dist[i]

            d = f; v = t
            while v != s:
                d = min(d, prv_e[v][1])
                v = prv_v[v]
            f -= d
            res += d * H[t]
            v = t
            while v != s:
                e = prv_e[v]
                e[1] -= d
                e[3][1] += d
                v = prv_v[v]
        return res
    
def main():
    n, m = map(int, input().split())
    mf = MinCostFlow(n)
    for _ in range(m):
        u, v, c, d = map(int, input().split())
        mf.add_edge(u-1, v-1, 1, c)
        mf.add_edge(u-1, v-1, 1, d)
        mf.add_edge(v-1, u-1, 1, c)
        mf.add_edge(v-1, u-1, 1, d)
    print(mf.flow(0, n-1, 2))

main()
0