結果
| 問題 | No.1479 Matrix Eraser |
| コンテスト | |
| ユーザー |
|
| 提出日時 | 2022-03-16 00:35:13 |
| 言語 | PyPy3 (7.3.15) |
| 結果 |
AC
|
| 実行時間 | 1,115 ms / 3,000 ms |
| コード長 | 3,709 bytes |
| 記録 | |
| コンパイル時間 | 565 ms |
| コンパイル使用メモリ | 82,400 KB |
| 実行使用メモリ | 174,084 KB |
| 最終ジャッジ日時 | 2024-09-22 17:10:12 |
| 合計ジャッジ時間 | 16,820 ms |
|
ジャッジサーバーID (参考情報) |
judge3 / judge4 |
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| ファイルパターン | 結果 |
|---|---|
| sample | AC * 2 |
| other | AC * 39 |
ソースコード
#Dinic法で最大流を求める
#deque のimport が必要
#逆辺追加しなきゃいけないから、
#グラフの構成はadd_edgeで行う
#最大流は flow メソッドで
from collections import deque
class Dinic:
def __init__(self,N):
self.N = N
self.G = [[] for _ in range(N)]
self.level = None
self.progress = None
self.edge = []
def add_edge(self,fr,to,cap):
forward = [to,cap,None]
forward[2] = backward = [fr,0,forward]
self.G[fr].append(forward)
self.G[to].append(backward)
self.edge.append(forward)
def add_multi_edge(self,v1,v2,cap1,cap2):
edge1 = [v2,cap1,None]
edge1[2] = edge2 = [v1,cap2,edge1]
self.G[v1].append(edge1)
self.G[v2].append(edge2)
self.edge.append(edge1)
def get_edge(self,i):
return self.edge[i]
# i 回目に追加した辺のポインタを返す
# 0-index, 順辺のみ
def bfs(self,s,t):
self.level = level = [None] * self.N
q = deque([s])
level[s] = 0
G = self.G
while q:
v = q.popleft()
lv = level[v] + 1
for w,cap,_ in G[v]:
if cap and level[w] is None:
level[w] = lv
q.append(w)
return level[t] is not None
def dfs(self, v, t, f):
if v == t:
return f
level = self.level
for e in self.it[v]:
w, cap, rev = e
if cap and level[v] < level[w]:
d = self.dfs(w, t, min(f, cap))
if d:
e[1] -= d
rev[1] += d
return d
else:
pass
else:
pass
return 0
def flow(self, s, t):
flow = 0
INF = 10**9 + 7
G = self.G
while self.bfs(s, t):
*self.it, = map(iter, self.G)
f = INF
while f:
f = self.dfs(s, t, INF)
flow += f
return flow
def min_cut(self,s):
#最小カットを実現する頂点の分割を与える
#True なら source側
#False なら sink側
visited = [False for i in range(self.N)]
q = deque([s])
while q:
now = q.popleft()
visited[now] = True
for to,cap,_ in self.G[now]:
if cap and not visited[to]:
visited[to] = True
q.append(to)
return visited
import sys
rr = sys.stdin
H,W = map(int,rr.readline().split())
A = [list(map(int,rr.readline().split())) for _ in range(H)]
d = [[] for _ in range(5 * 10 ** 5 + 1)]
s = set()
for h in range(H):
for w in range(W):
d[A[h][w]].append((h,w))
s.add(A[h][w])
inf = 1 << 30
ans = 0
for k in s:
if k == 0:continue
l = d[k]
if len(l) == 1:
ans += 1
continue
elif len(l) == 2:
if l[0][0] == l[1][0] or l[0][1] == l[1][1]:
ans += 1
else:
ans += 2
continue
ch = set()
cw = set()
for h,w in l:
ch.add(h)
cw.add(w)
rDh = sorted(ch)
rDw = sorted(cw)
Dh = {v:i for i,v in enumerate(rDh)}
Dw = {v:i for i,v in enumerate(rDw)}
n = len(Dh) + len(Dw)
dinic = Dinic(n + 2)
T = n + 1
base = len(Dh)
for h,w in l:
dinic.add_edge(Dh[h]+1,base + Dw[w] + 1,inf)
for i in range(base):
dinic.add_edge(0,i+1,1)
for i in range(len(Dw)):
dinic.add_edge(base + i + 1,T,1)
ans += dinic.flow(0,T)
print(ans)