結果

問題 No.1301 Strange Graph Shortest Path
ユーザー chineristAC
提出日時 2020-11-27 21:25:09
言語 PyPy3
(7.3.15)
結果
AC  
実行時間 1,189 ms / 3,000 ms
コード長 1,892 bytes
コンパイル時間 372 ms
コンパイル使用メモリ 82,340 KB
実行使用メモリ 210,488 KB
最終ジャッジ日時 2024-09-13 00:50:13
合計ジャッジ時間 35,269 ms
ジャッジサーバーID
(参考情報)
judge1 / judge3
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ファイルパターン 結果
sample AC * 2
other AC * 33
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ソースコード

diff #
プレゼンテーションモードにする

import random
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
import sys
input = sys.stdin.readline
N,M = map(int,input().split())
G = MinCostFlow(N)
for _ in range(M):
u,v,c,d = map(int,input().split())
G.add_edge(u-1,v-1,1,c)
G.add_edge(u-1,v-1,1,d)
G.add_edge(v-1,u-1,1,c)
G.add_edge(v-1,u-1,1,d)
print(G.flow(0,N-1,2))
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