Const
N = 10;
var
mas:array[1..999] of integer;
i:integer;
begin
randomize;
write('Массив: ');
for i:=1 to N do
begin
mas[i]:=random(21)-10;
write(mas[i],' ');
end;
writeln;
for i:=1 to N div 2 do
mas[i]:=-mas[i];
for i:=(N div 2)+1 to N do
mas[i]:=-mas[i];
write('Новый массив: ');
for i:=1 to N do
write(mas[i], ' ');
end.