比较简单的费用流，一目了然
1 const inf=10000007; 2 type node=record 3 next,point,flow,cost:longint; 4 end; 5 6 var edge:array[0..200010] of node; 7 q:array[0..200010] of longint; 8 p,d,pre,cur,u,w:array[0..200] of longint; 9 v:array[0..200] of boolean; 10 s,i,len,n,m,t:longint; 11 12 function min(a,b:longint):longint; 13 begin 14 if a>b then exit(b) else exit(a); 15 end; 16 17 procedure add(x,y,f,c:longint); 18 begin 19 inc(len); 20 edge[len].point:=y; 21 edge[len].flow:=f; 22 edge[len].cost:=c; 23 edge[len].next:=p[x]; 24 p[x]:=len; 25 end; 26 27 function spfa:boolean; 28 var y,i,f,r,x:longint; 29 begin 30 d[0]:=0; 31 for i:=1 to t do 32 d[i]:=inf; 33 f:=1; 34 r:=1; 35 q[1]:=0; 36 fillchar(v,sizeof(v),false); 37 v[0]:=true; 38 while f<=r do 39 begin 40 x:=q[f]; 41 v[x]:=false; 42 i:=p[x]; 43 while i<>-1 do 44 begin 45 y:=edge[i].point; 46 if edge[i].flow>0 then 47 if d[y]>d[x]+edge[i].cost then 48 begin 49 d[y]:=d[x]+edge[i].cost; 50 pre[y]:=x; 51 cur[y]:=i; 52 if not v[y] then 53 begin 54 inc(r); 55 q[r]:=y; 56 v[y]:=true; 57 end; 58 end; 59 i:=edge[i].next; 60 end; 61 inc(f); 62 end; 63 if d[t]=inf then exit(false) else exit(true); 64 end; 65 66 function mincost:longint; 67 var neck,i,j:longint; 68 begin 69 mincost:=0; 70 while spfa do 71 begin 72 neck:=inf; 73 i:=t; 74 while i<>0 do 75 begin 76 j:=cur[i]; 77 neck:=min(neck,edge[j].flow); 78 i:=pre[i]; 79 end; 80 i:=t; 81 while i<>0 do 82 begin 83 j:=cur[i]; 84 dec(edge[j].flow,neck); 85 inc(edge[j xor 1].flow,neck); 86 i:=pre[i]; 87 end; 88 mincost:=mincost+d[t]*neck; 89 end; 90 end; 91 92 begin 93 len:=-1; 94 fillchar(p,sizeof(p),255); 95 readln(n,m,s); 96 t:=n+1; 97 for i:=1 to n do 98 read(u[i]); 99 for i:=1 to n do 100 begin 101 read(w[i]); 102 add(0,i,inf,w[i]); 103 add(i,0,0,-w[i]); 104 add(i,t,u[i],0); 105 add(t,i,0,0); 106 if i<>n then 107 begin 108 add(i,i+1,s,m); 109 add(i+1,i,0,-m); 110 end; 111 end; 112 writeln(mincost); 113 end.
