Bzoj1221: [hnoi2001] Software Development

1221: [hnoi2001] software development time limit: 10 sec memory limit: 162 MB
Submit: 503 solved: 265
[Submit] [Status] Description

A software company is planning a software development plan for N days. According to the development plan, ni software developers are required on day I. To improve the efficiency of software developers, the company has provided a lot of services to software personnel. One of the services is to provide each developer with a sterile towel every day, which can only be used after being disinfected for one day. There are two disinfection methods: Method A and method B (B> ), the cost of a disinfection method is Fa for each towel, and the cost of B disinfection method is fb for each towel, and the cost of buying a new towel is F (the new towel is disinfected, can be used on the current day), and F> fa> FB. The company manager is planning how many new towels are bought each day during the N days, how many towels are sent each day for a type of disinfection, and how many towels are sent each day for B type of disinfection. Of course, the company manager wants the lowest cost. Your task is to plan how many towels to buy for the software company, how many towels to disinfect a and how many towels to disinfect a day, this minimizes the total cost of providing towel services during the n-day software development.

Input

1st behavior n, A, B, F, fa, FB. 2nd behavior N1, N2 ,......, Nn. (Note: 1 ≤ F, fa, FB ≤ 60, 1 ≤ n ≤ 1000)

Output

Minimum fee

Sample input4 1 2 3 2 1
8 2 1 6
Sample output 38
Hint Source

Maximum Flow with minimum cost

Question: Is this question different from the napkin plan ?... I did not say that I could leave it for the next day to wash my questions, causing my wa code:

  1 const inf=maxlongint;  2 type node=record  3      from,go,next,v,c:longint;  4      end;  5 var e:array[0..2000000] of node;  6     pre,head,q,d:array[0..1000000] of longint;  7     v:array[0..1000000] of boolean;  8     i,j,n,m,maxf,s,t,l,r,mincost,tot,a,b,fa,fb,f,x:longint;  9 function min(x,y:longint):longint; 10  begin 11  if x<y then exit(x) else exit(y); 12  end; 13 procedure ins(x,y,z,w:longint); 14  begin 15  inc(tot); 16  with e[tot] do 17   begin 18   from:=x;go:=y;v:=z;c:=w;next:=head[x];head[x]:=tot; 19   end; 20  end; 21 procedure insert(x,y,z,w:longint); 22  begin 23  ins(x,y,z,w);ins(y,x,0,-w); 24  end; 25 function spfa:boolean; 26  var i,x,y:longint; 27  begin 28  fillchar(v,sizeof(v),false); 29  for i:=s to t do d[i]:=inf; 30  l:=0;r:=1;q[1]:=s;d[s]:=0;v[s]:=true; 31  while l<r do 32   begin 33   inc(l); 34   x:=q[l];v[x]:=false; 35   i:=head[x]; 36   while i<>0 do 37    begin 38    y:=e[i].go; 39    if (e[i].v<>0) and (d[x]+e[i].c<d[y]) then 40     begin 41     d[y]:=d[x]+e[i].c; 42     pre[y]:=i; 43     if not(v[y]) then 44      begin 45      v[y]:=true; 46      inc(r); 47      q[r]:=y; 48      end; 49     end; 50    i:=e[i].next; 51   end; 52  end; 53  exit(d[t]<>inf); 54  end; 55 procedure mcf; 56  var i,tmp:longint; 57  begin 58  mincost:=0; 59  while spfa do 60   begin 61   tmp:=inf; 62   i:=pre[t]; 63   while i<>0 do 64    begin 65    tmp:=min(tmp,e[i].v); 66    i:=pre[e[i].from]; 67    end; 68   inc(mincost,tmp*d[t]); 69   i:=pre[t]; 70   while i<>0 do 71    begin 72    dec(e[i].v,tmp); 73    inc(e[i xor 1].v,tmp); 74    i:=pre[e[i].from]; 75    end; 76   end; 77  end; 78 procedure init; 79  begin 80  tot:=1; 81  readln(n,a,b,f,fa,fb); 82  s:=0;t:=2*n+1; 83  for i:=1 to n do 84   begin 85   read(x); 86   insert(i+n,t,x,0); 87   insert(s,i,x,0); 88   insert(s,i+n,x,f); 89   if i+1<=n then insert(i,i+1,inf,0); 90   if i+a+1<=n then insert(i,i+a+n+1,inf,fa); 91   if i+b+1<=n then insert(i,i+b+n+1,inf,fb); 92   end; 93  94  end; 95 procedure main; 96  begin 97  mincost:=0; 98  mcf; 99  writeln(mincost);100  end;101 begin102  assign(input,‘input.txt‘);assign(output,‘output.txt‘);103  reset(input);rewrite(output);104  init;105  main;106  close(input);close(output);107 end.  

View code