Mooo Moo题解

一眼看出是完全背包

设f[i]表示哞哞叫总音量为i时最少需要几头奶牛

a[i]为在第i个草场听到的哞哞叫总音量

则第i个草场自己的哞哞叫音量为a[i]-a[i-1]-1

代码呼之欲出

uses math;
var
  f:array[1..100000]of longint;
  v:array[1..100]of longint;
  a:array[1..20]of longint;
  n,b,i,j,s:longint;
begin
  fillchar(f,sizeof(f),127);
  read(n,b);
  for i:=1 to n do read(v[i]);
  for i:=1 to b do read(a[i]);
  for i:=1 to b do
   for j:=v[i]to 100000 do f[j]:=min(f[j],f[j-v[i]]+1);
  a[0]:=1;
  for i:=1 to n do
   begin
    inc(s,f[a[i]-a[i-1]+1]);
    if a[i]=0 then a[i]:=1;
   end;
  if s>100000 then write(-1)else write(s);
end.