[Hb2014 week5] allot personnel allocation

These two days I am determined to do a good job in Network Flow --

What is the problem? I am talking about connecting N + 2 and N + 1 with infinite capacity... I read about STD...

The point is that you need to request multiple network streams. Don't forget to clear the stream every time... This time, I wrote a clearflow process using a linked list. If it is a static linked list, I can use fillchar...

program allot2;type ptype=^node;     node=record            v,w,flow:longint;            next:ptype;          end;const maxn=400+10;      inf=maxlongint;var m,n,k,i,j,x,y,l,mid,r,sta,tar:longint;    head:array[1..maxn] of ptype;    q,d:array[1..maxn] of longint;    visit:array[1..maxn] of boolean;function min(a,b:longint):longint;begin  if a>b then exit(b) else exit(a);end;procedure insert(st,ed,r:longint);var p,q,pre:ptype;begin  //if (st=n+1) or (st=n+2) then r:=inf;  //if (ed=n+1) or (ed=n+2) then r:=0;  new(p);new(q);  p^.v:=ed;p^.w:=r;p^.flow:=0;p^.next:=nil;  q:=head[st];  if q=nil then    begin      new(head[st]);      head[st]^:=p^;    end  else    begin      while q<>nil do        begin          pre:=q;q:=q^.next;        end;      new(q);      q^:=p^;      pre^.next:=q;    end;end;procedure decflow(st,ed,delta:longint);var x,y:ptype;begin  y:=head[st];  while y^.v<>ed do y:=y^.next;  y^.flow:=y^.flow-delta;end;function bfs:boolean;var star,rear,x:longint;    y:ptype;begin  fillchar(visit,sizeof(visit),false);  fillchar(q,sizeof(q),0);  fillchar(d,sizeof(d),0);  star:=1;rear:=1;q[star]:=sta;visit[sta]:=true;d[star]:=1;  while star<=rear do    begin      x:=q[star];      y:=head[x];      while y<>nil do        begin          if (visit[y^.v]=false) and (y^.w>y^.flow) then            begin              inc(rear);              q[rear]:=y^.v;              visit[y^.v]:=true;              d[y^.v]:=d[x]+1;            end;          y:=y^.next;        end;      inc(star);    end;  bfs:=visit[tar];end;function addflow(p,maxflow:longint):longint;var x,y:ptype;    o:longint;begin  if (p=tar) or (maxflow=0) then exit(maxflow);  y:=head[p];addflow:=0;  while y<>nil do    begin      if (d[y^.v]=d[p]+1) and (y^.w>y^.flow) then        begin          o:=addflow(y^.v,min(maxflow,y^.w-y^.flow));          if o>0 then            begin              inc(y^.flow,o);              decflow(y^.v,p,o);              inc(addflow,o);              dec(maxflow,o);              if maxflow=0 then break; //!            end;        end;      y:=y^.next;    end;end;function network:longint;begin  network:=0;  while bfs do    inc(network,addflow(sta,inf));end;procedure clearflow;  //!var i,j:longint;    y:ptype;begin  for i:=1 to n+3 do    begin      y:=head[i];      while y<>nil do        begin          y^.flow:=0;          y:=y^.next;;        end;    end;end;begin  assign(input,‘allot9.in‘);reset(input);  assign(output,‘allot9.out‘);rewrite(output);  readln(n,m,k);  //build_graph;  for i:=1 to m do    begin      readln(x,y,l,mid,r);      insert(y,x,mid-l);      insert(x,y,r-mid);    end;  insert(n+3,n+2,inf);insert(n+2,n+3,0);  insert(n+3,n+1,inf);insert(n+1,n+3,0);  //main  sta:=n+3;  for i:=1 to n do    begin      clearflow;      tar:=i;      if network>=k then writeln(‘1‘) else writeln(‘0‘);    end;end.

Allot

When I write the network stream myself, I forget the sentence if maxflow = 0 Then exit. Although it does not affect the result, it will affect the speed.

Running on your computer is a little slow and you don't know where OJ has... Sigh...