洛谷 P1909 买铅笔

暴力轻松AC
每一种包装都记录买当前包装最少要买几次才能使数量大于等于N，再记录包装单价与次数的乘积，对比找最小。

var     a:array [1..3,1..2] of longint;     i,n,min,now,money:longint;begin    assign(input,'pencil.in');      reset(input);    assign(output,'pencil.out');               rewrite(output);    min:=maxlongint;    readln(n);    for i:=1 to 3 do        begin            readln(a[i,1],a[i,2]);            now:=0; money:=0;            while now<n do                  begin                      now:=now+a[i,1];                      money:=money+a[i,2];                  end;            if min>money then min:=money;        end;    writeln(min);    close(input);  close(output);end.