明显的单调队列……
但下面的程序一直有bug
附上题解：http://blog.csdn.net/njlcazl/article/details/8611042
附上我的代码：
1 var head,tail,i,n,maxp,w,t,ans,j:longint;
2 as,bs,ap,bp,q,val:array[0..2020] of longint;
3 f:array[0..2020,0..2020] of longint;
4 function max(x,y:longint):longint;
5 begin
6 if x>y then exit(x) else exit(y);
7 end;
8 procedure init;
9 begin
10 readln(n,maxp,w);ans:=0;
11 for i:=1 to n do readln(ap[i],bp[i],as[i],bs[i]);
12 end;
13 procedure main;
14 begin
15 fillchar(f,sizeof(f),128);
16 f[0,0]:=0;
17 for i:=1 to n do
18 begin
19 for j:=0 to as[i] do f[i,j]:=-j*ap[i];
20 for j:=0 to as[i] do
21 f[i,j]:=max(f[i,j],f[i-1,j]);
22 t:=i-w-1;
23 if t>=0 then
24 begin
25 head:=0;tail:=0;
26 for j:=0 to maxp do
27 begin
28 while (head<tail) and (q[head]<j-as[i]) do inc(head);
29 while (head<tail) and (f[t,j]+j*ap[i]>=val[tail-1]) do dec(tail);
30 val[tail]:=f[t,j]+j*ap[i];
31 q[tail]:=j;inc(tail);
32 if head<tail then f[i,j]:=max(f[i,j],val[head]-j*ap[i]);
33 end;
34 head:=0;tail:=0;
35 for j:=maxp downto 0 do
36 begin
37 while (head<tail) and (q[head]>j+bs[i]) do inc(head);
38 while (head<tail) and (f[t,j]+j*bp[i]>=val[tail-1]) do dec(tail);
39 val[tail]:=f[t,j]+j*bp[i];
40 q[tail]:=j;inc(tail);
41 if head<tail then f[i,j]:=max(f[i,j],val[head]-j*bp[i]);
42 end;
43 end;
44 ans:=max(ans,f[i,0]);
45 end;
46 writeln(ans);
47 end;
48 begin
49 init;
50 main;
51 end.
还有另一位oier的代码：
1 type
2 ji=record
3 w,s:longint;
4 end;
5 var
6 q:array[0..2005] of ji;
7 f:array[-2000..2000,0..2000] of longint;
8 x,i,j,k,head,tail,t,maxp,w,api,bpi,asi,bsi:longint;
9
10 function max(x,y:longint):longint;
11 begin
12 if x>y then exit(x);
13 exit(y);
14 end;
15
16 begin
17 readln(t,maxp,w);
18 for i:=-t to t do
19 for j:=1 to maxp do
20 f[i,j]:=-1000000000;
21 for i:=1 to t do
22 begin
23 readln(api,bpi,asi,bsi);
24 head:=1;
25 tail:=1;
26 f[i]:=f[i-1];
27 q[1].s:=0;
28 q[1].w:=f[i-w-1,0];
29 for j:=1 to maxp do
30 begin
31 inc(tail);
32 q[tail].w:=f[i-w-1,j]+j*api;
33 q[tail].s:=j;
34 while (head<tail)and(q[tail-1].w<q[tail].w) do
35 begin
36 q[tail-1]:=q[tail];
37 dec(tail);
38 end;
39 while (head<=tail)and(q[tail].s<j-asi) do inc(head);
40 f[i,j]:=max(f[i,j],q[head].w-api*j);
41 end;
42 head:=1;
43 tail:=1;
44 q[1].s:=maxp;
45 q[1].w:=f[i-w-1,maxp]+maxp*bpi;
46 for j:=maxp-1 downto 0 do
47 begin
48 inc(tail);
49 q[tail].w:=f[i-w-1,j]+j*bpi;
50 q[tail].s:=j;
51 while (head<=tail)and(q[tail].w<x) do
52 begin
53 q[tail-1]:=q[tail];
54 dec(tail);
55 end;
56 while (head<=tail)and(q[head].s>j+bsi) do inc(head);
57 f[i,j]:=max(f[i,j],q[head].w-j*bpi);
58 end;
59 end;
60 writeln(f[t,0]);
61 end.
这两种代码方法是一样的，但求解的过程不一样，可以挑选自己喜欢的来写。
ps：这两个代码都有bug，在bzoj上都是wa……
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时间： 2024-08-22 16:33:22