二维代码：

var

n,i,j,k,h,tot:integer;

f:array[0..2000,0..2000] of boolean;

a:array[1..100] of integer;

begin

readln(n);

fillchar(f,sizeof(f),false);

for i:=1 to n do

begin

read(a[i]);

h:=h+a[i];

tot:=h div 2;

end;

f[0,0]:=true;

for k:=1 to n do

begin

for i:=tot downto 0 do

for j:=tot downto 0 do

if not f then

if (i>=a[k]) and (f[i-a[k],j])

then f:=true

else if (j>=a[k]) and (f[i,j-a[k]])

then f:=true;

end;

for i:=h downto 1 do

if f then

begin

writeln(i);

halt;

end;

writeln('Impossible');

end.

一维代码：

var

f:array[0..2000]of boolean;

a:array[1..100]of integer;

n,i,j,h:integer;

begin

readln(n);

fillchar(f,sizeof(f),false);

for i:=1 to n do

read(a[i]);

h:=0;

f[0]:=true;

for i:=1 to n do

begin

h:=h+a[i];

for j:=h downto a[i] do

if f[j-a[i]] then f[j]:=true;

end;

i:=1001;

repeat

dec(i);

until (i=0) or ((f[i]) and (f));

if (i=0)

then writeln('Impossible')

else writeln(i);

end.