結果
問題 | No.1301 Strange Graph Shortest Path |
ユーザー | shakayami |
提出日時 | 2020-11-27 23:36:35 |
言語 | PyPy3 (7.3.15) |
結果 |
AC
|
実行時間 | 2,494 ms / 3,000 ms |
コード長 | 4,167 bytes |
コンパイル時間 | 285 ms |
コンパイル使用メモリ | 87,192 KB |
実行使用メモリ | 418,924 KB |
最終ジャッジ日時 | 2023-10-10 21:49:02 |
合計ジャッジ時間 | 69,490 ms |
ジャッジサーバーID (参考情報) |
judge12 / judge13 |
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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 | 75 ms
71,592 KB |
testcase_01 | AC | 75 ms
71,528 KB |
testcase_02 | AC | 2,217 ms
407,304 KB |
testcase_03 | AC | 2,057 ms
369,540 KB |
testcase_04 | AC | 2,295 ms
418,752 KB |
testcase_05 | AC | 2,230 ms
411,568 KB |
testcase_06 | AC | 2,138 ms
389,796 KB |
testcase_07 | AC | 2,111 ms
395,140 KB |
testcase_08 | AC | 1,975 ms
372,708 KB |
testcase_09 | AC | 1,766 ms
374,356 KB |
testcase_10 | AC | 1,776 ms
371,636 KB |
testcase_11 | AC | 1,984 ms
402,484 KB |
testcase_12 | AC | 1,931 ms
403,116 KB |
testcase_13 | AC | 1,924 ms
410,980 KB |
testcase_14 | AC | 2,155 ms
373,580 KB |
testcase_15 | AC | 1,794 ms
379,196 KB |
testcase_16 | AC | 2,202 ms
418,924 KB |
testcase_17 | AC | 2,083 ms
416,632 KB |
testcase_18 | AC | 2,109 ms
385,172 KB |
testcase_19 | AC | 1,811 ms
392,224 KB |
testcase_20 | AC | 2,050 ms
386,304 KB |
testcase_21 | AC | 2,048 ms
409,424 KB |
testcase_22 | AC | 2,243 ms
394,356 KB |
testcase_23 | AC | 1,949 ms
413,028 KB |
testcase_24 | AC | 2,176 ms
389,868 KB |
testcase_25 | AC | 2,194 ms
417,716 KB |
testcase_26 | AC | 2,356 ms
394,792 KB |
testcase_27 | AC | 1,943 ms
401,912 KB |
testcase_28 | AC | 2,027 ms
395,780 KB |
testcase_29 | AC | 2,494 ms
416,756 KB |
testcase_30 | AC | 2,067 ms
415,100 KB |
testcase_31 | AC | 2,118 ms
413,320 KB |
testcase_32 | AC | 76 ms
71,336 KB |
testcase_33 | AC | 1,242 ms
408,108 KB |
testcase_34 | AC | 2,011 ms
417,612 KB |
ソースコード
import heapq class mcf_graph(): n=1 pos=[] g=[[]] def __init__(self,N): self.n=N self.pos=[] self.g=[[] for i in range(N)] def add_edge(self,From,To,cap,cost): assert 0<=From and From<self.n assert 0<=To and To<self.n m=len(self.pos) self.pos.append((From,len(self.g[From]))) self.g[From].append({"to":To,"rev":len(self.g[To]),"cap":cap,"cost":cost}) self.g[To].append({"to":From,"rev":len(self.g[From])-1,"cap":0,"cost":-cost}) def get_edge(self,i): m=len(self.pos) assert 0<=i and i<m _e=self.g[self.pos[i][0]][self.pos[i][1]] _re=self.g[_e["to"]][_e["rev"]] return {"from":self.pos[i][0],"to":_e["to"],"cap":_e["cap"]+_re["cap"], "flow":_re["cap"],"cost":_e["cost"]} def edges(self): m=len(self.pos) result=[{} for i in range(m)] for i in range(m): tmp=self.get_edge(i) result[i]["from"]=tmp["from"] result[i]["to"]=tmp["to"] result[i]["cap"]=tmp["cap"] result[i]["flow"]=tmp["flow"] result[i]["cost"]=tmp["cost"] return result def flow(self,s,t,flow_limit=(1<<63)-1): return self.slope(s,t,flow_limit)[-1] def slope(self,s,t,flow_limit=(1<<63)-1): assert 0<=s and s<self.n assert 0<=t and t<self.n assert s!=t ''' variants (C = maxcost): -(n-1)C <= dual[s] <= dual[i] <= dual[t] = 0 reduced cost (= e.cost + dual[e.from] - dual[e.to]) >= 0 for all edge ''' dual=[0 for i in range(self.n)] dist=[0 for i in range(self.n)] pv=[0 for i in range(self.n)] pe=[0 for i in range(self.n)] vis=[False for i in range(self.n)] def dual_ref(): for i in range(self.n): dist[i]=(1<<63)-1 pv[i]=-1 pe[i]=-1 vis[i]=False que=[] heapq.heappush(que,(0,s)) dist[s]=0 while(que): v=heapq.heappop(que)[1] if vis[v]:continue vis[v]=True if v==t:break ''' dist[v] = shortest(s, v) + dual[s] - dual[v] dist[v] >= 0 (all reduced cost are positive) dist[v] <= (n-1)C ''' for i in range(len(self.g[v])): e=self.g[v][i] if vis[e["to"]] or (not(e["cap"])):continue ''' |-dual[e.to]+dual[v]| <= (n-1)C cost <= C - -(n-1)C + 0 = nC ''' cost=e["cost"]-dual[e["to"]]+dual[v] if dist[e["to"]]-dist[v]>cost: dist[e["to"]]=dist[v]+cost pv[e["to"]]=v pe[e["to"]]=i heapq.heappush(que,(dist[e["to"]],e["to"])) if not(vis[t]): return False for v in range(self.n): if not(vis[v]):continue dual[v]-=dist[t]-dist[v] return True flow=0 cost=0 prev_cost=-1 result=[(flow,cost)] while(flow<flow_limit): if not(dual_ref()): break c=flow_limit-flow v=t while(v!=s): c=min(c,self.g[pv[v]][pe[v]]["cap"]) v=pv[v] v=t while(v!=s): self.g[pv[v]][pe[v]]["cap"]-=c self.g[v][self.g[pv[v]][pe[v]]["rev"]]["cap"]+=c v=pv[v] d=-dual[s] flow+=c cost+=c*d if(prev_cost==d): result.pop() result.append((flow,cost)) prev_cost=cost return result N,M=map(int,input().split()) G=mcf_graph(N) for _ in range(M): u,v,c,d=map(int,input().split()) u-=1;v-=1 G.add_edge(u,v,1,c) G.add_edge(v,u,1,c) G.add_edge(u,v,1,d) G.add_edge(v,u,1,d) result=G.flow(0,N-1,flow_limit=2) print(result[1])