[BZOJ1531] [POI2005]Bank notes

传送门

题目大意

题解

var
dp:array[0..20000]of longint;
y:array[0..200,1..2]of longint;
x:array[0..3000,1..2]of longint;
i,j,k:longint;
n,m,len,a:longint;
function min(a,b:longint):longint;
begin
if a<b then exit(a) else exit(b);
end;

begin
readln(k);
for i:=1 to k do
read(y[i,1]);
for i:=1 to k do
read(y[i,2]);
readln(m);
len:=0;
for i:=1 to k do begin
a:=1;
while a<y[i,2] do
begin inc(len); x[len,1]:=y[i,1]*a; x[len,2]:=a; a:=a<<1; end;
inc(len);
if a>y[i,2] then x[len,2]:=y[i,2]-a>>1+1 else x[len,2]:=y[i,2]-a+1;
x[len,1]:=x[len,2]*y[i,1];
end;
dp[0]:=0;
for i:=1 to m do
dp[i]:=1000000000;
for i:=1 to len do
for j:=m downto x[i,1] do
dp[j]:=min(dp[j],dp[j-x[i,1]]+x[i,2]);
writeln(dp[m]);
{for i:=1 to len do
writeln(x[i,1],' ',x[i,2]);}
end.