結果

問題 No.1301 Strange Graph Shortest Path
ユーザー wolgnikwolgnik
提出日時 2020-11-27 22:57:32
言語 PyPy3
(7.3.15)
結果
WA  
実行時間 -
コード長 3,373 bytes
コンパイル時間 249 ms
コンパイル使用メモリ 81,980 KB
実行使用メモリ 309,220 KB
最終ジャッジ日時 2024-07-26 20:15:32
合計ジャッジ時間 63,425 ms
ジャッジサーバーID
（参考情報） 		judge5 / judge3
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 40 ms
53,944 KB
testcase_01 AC 40 ms
54,108 KB
testcase_02 WA -
testcase_03 AC 1,737 ms
277,144 KB
testcase_04 AC 1,980 ms
303,440 KB
testcase_05 AC 1,906 ms
303,792 KB
testcase_06 AC 1,894 ms
301,052 KB
testcase_07 AC 2,096 ms
303,356 KB
testcase_08 AC 1,813 ms
275,300 KB
testcase_09 AC 1,759 ms
293,196 KB
testcase_10 WA -
testcase_11 AC 1,716 ms
299,800 KB
testcase_12 AC 1,959 ms
306,864 KB
testcase_13 AC 1,888 ms
297,712 KB
testcase_14 AC 2,211 ms
292,584 KB
testcase_15 AC 1,799 ms
290,384 KB
testcase_16 AC 1,893 ms
299,620 KB
testcase_17 AC 1,890 ms
299,756 KB
testcase_18 AC 2,040 ms
292,388 KB
testcase_19 AC 1,855 ms
295,104 KB
testcase_20 AC 1,748 ms
299,792 KB
testcase_21 AC 2,013 ms
305,612 KB
testcase_22 AC 1,730 ms
293,664 KB
testcase_23 AC 1,905 ms
303,516 KB
testcase_24 AC 1,945 ms
300,504 KB
testcase_25 AC 2,163 ms
299,768 KB
testcase_26 AC 2,104 ms
295,528 KB
testcase_27 AC 1,860 ms
308,204 KB
testcase_28 AC 1,868 ms
295,952 KB
testcase_29 WA -
testcase_30 AC 1,959 ms
302,592 KB
testcase_31 AC 2,165 ms
298,496 KB
testcase_32 WA -
testcase_33 WA -
testcase_34 AC 1,979 ms
301,912 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
input = sys.stdin.readline
N, M = map(int, input().split())

from heapq import heappop, heappush, heapify
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

mcf = MinCostFlow(N)
edges = []
for _ in range(M):
  u, v, c, d = map(int, input().split())
  edges.append((u, v, c, d))
  mcf.add_edge(u - 1, v - 1, 1, c)
  mcf.add_edge(v - 1, u - 1, 1, c)
mcf2 = mcf.flow_with_limit(0, N - 1, 2)
mcf = MinCostFlow(N)
for u, v, c, d in edges:
  mcf.add_edge(u - 1, v - 1, 1, c)
  mcf.add_edge(v - 1, u - 1, 1, c)
mcf1 = mcf.flow_with_limit(0, N - 1, 1)
if mcf2[0] == 2 and mcf1[1] * 2 == mcf2[1]:
  print(mcf2[1])
  exit(0)
mcfedges = list(mcf.edges())
mcf = MinCostFlow(N)
for i in range(M):
  x = i * 2
  fr, to, cap, flow, cost = mcfedges[x]
  flow += mcfedges[x + 1][3]
  if flow: 
    mcf.add_edge(fr, to, cap, edges[i][-1])
    mcf.add_edge(to, fr, cap, edges[i][-1])
  else: 
    mcf.add_edge(fr, to, cap, cost)
    mcf.add_edge(to, fr, cap, cost)
print(mcf1[1] + mcf.flow_with_limit(0, N - 1, 1)[1])
0