UVA 10801 Lift Hopping elevator transfer (shortest way, deformation)

Test instructions: There is a n<6 elevator, give each elevator can stop some of the specific floors, request from 0 floor to reach the K-level out, each transfer takes 60 seconds, each elevator through each floor time is different, specific by the number of floors * elevator speed to calculate. Q How many seconds to reach the K-level (K can be 0)?

Idea: Dijkstra add some special treatment on the line. The first thing to consider is how to build the diagram:

(1) Each layer as a point. But the specific path can have a variety of rights, such as from 2->5 can sit 1th elevator 10s, but sit 2nd only need 5s, so there are heavy edges.

(2) When k=0, it is not time-consuming.

(3) There are many ways to reach the same floor and the same weight, then from the floor to another floor has a variety of options, sometimes can not change elevators, sometimes need to change. For example, reached the 5 floor has 2 paths, the right is 5, but two different elevators 1 and 2, at this time there are other elevators from 5 to 7 floors, one of which is still elevator 1, if the elevator 1 does not need to transfer time, sitting other elevators will be. So you have to record an elevator number that is equal to a point weight.

1#include <bits/stdc++.h>2 #defineLL Long Long3 #definePII pair<int,int>4 #defineINF 0x7f7f7f7f5 using namespacestd;6 Const intn=1010;7 inttake[6];8 Chars[ +];9vector<int> lift[6], vect[ -];Ten intCost[n], vis[n]; One structnode A { -     int  from, to, lift, cost; - node () {}; theNodeint  from,intTo,intLiftintCost): from( from), to, lift (lift), cost (cost) {}; -}edge[100000]; - intedge_cnt; -  + voidAdd_node (int  from,intTo,intLiftintCost ) - { +Edge[edge_cnt]=node ( from, to,lift,cost); Avect[ from].push_back (edge_cnt++); at } -  - voidBuild_graph (intN//re-build the map - { -      for(intI=0; i<n; i++) -     { in          for(intj=0; J<lift[i].size (); J + +) -         { to              for(intt=j+1; T<lift[i].size (); t++) +             { -                 intA=Lift[i][j]; the                 intb=Lift[i][t]; *Add_node (A,b,i, (b-a) *take[i]); $Add_node (B,a,i, (b-a) *take[i]);Panax Notoginseng             } -         } the     } + } A  the intDijkstraintSinte) + { -vector<int> flo[101]; $memset (Cost,0x7f,sizeof(cost)); $memset (Vis,0,sizeof(Vis)); -  -priority_queue<pii,vector<pii>,greater<pii> >que; theQue.push (Make_pair (0, s)); -cost[s]=0;Wuyi      while(!que.empty ()) the     { -         intx=que.top (). Second;que.pop (); Wu         if(Vis[x])Continue; -  Aboutvis[x]=1; $          for(intI=0; I<vect[x].size (); i++) -         { -Node e=Edge[vect[x][i]]; -             intext= -; A  +              for(intj=0; J<flo[e. from].size (); J + +)//If there is a match, there is no extra time the                 if(Flo[e. from][j]==e.lift) ext=0; -  $             if(Cost[e.to]>=cost[e. from]+ext+e.cost) the             { the                 if(Cost[e.to]>cost[e. from]+ext+e.cost) flo[e.to].clear (); the Flo[e.to].push_back (e.lift); the  -Cost[e.to]= cost[e. from] +ext +E.cost; in Que.push (Make_pair (cost[e.to], e.to)); the             } the         } About     } the     returnCost[e]; the } the  + intMain () - { theFreopen ("Input.txt","R", stdin);Bayi     intN, K; the      while(~SCANF ("%d%d",&n,&k)) the     { -          for(intI=0; i<n; i++) lift[i].clear (); -          for(intI=0; i<101; i++) vect[i].clear (); thememset (s),0,sizeof(s)); the  the          for(intI=0; i<n; i++) scanf ("%d",&take[i]); the GetChar (); -          for(intI=0; i<n; i++) the         { the lift[i].clear (); the gets (s);94             intp=0; the              while(s[p]!=' /') the             { the                 if(s[p]==' ') p++;98                 inttmp=0; About                  while(s[p]!=' '&&s[p]!=' /') tmp=tmp*Ten+ (s[p++]-'0'); - Lift[i].push_back (TMP);101             }102         }103 build_graph (n);104         intAns=dijkstra (0, k); the         if(!k) puts ("0");106         Else if(Ans==inf) puts ("Impossible");107         Elseprintf"%d\n", ans- - ) ;108     }109     return 0; the}

AC Code

UVA 10801 Lift Hopping elevator transfer (shortest way, deformation)