745 / Л.Р.№3 / Lab3_var_4

Program LAB_3;
uses crt;
var a,b,c,b1:string;
i,j:integer;

Procedure SWAP(var a:string);
var i:integer;
Begin
i:=length(a);
while a[i]<>'1' do dec(i);
for i:=i-1 downto 1 do if a[i]='0' then a[i]:='1'
else a[i]:='0';
insert('00000000',a,9);
end;

procedure SUM(var b,c:string);
var j,r:integer;
begin
r:=0;
for j:=16 downto 1 do
begin
if ord(b[j])+ord(c[j])-96+r>1 then
begin
if ord(b[j])+ord(c[j])-96+r>2 then c[j]:='1'
else c[j]:='0';
r:=1;
end
else
begin
if ord(b[j])+ord(c[j])-96+r=1 then c[j]:='1'
else c[j]:='0';
r:=0;
end;
end;
end;

Function ERROR(a:string):boolean;
var i:integer;
begin
ERROR:=TRUE;
if length(a)<>8 then ERROR:=FALSE
else for i:=1 to length(a) do if (a[i]<>'1')and(a[i]<>'0') then ERROR:=false;
end;

Begin
clrscr;
writeln('A,B-?');
readln(b);
readln(a);
b1:=b;
if (ERROR(a))and(ERROR(b)) then
begin
insert('0000000',b,9);
insert('0',b,1);
c:='0000000000000000';
for i:=8 downto 1 do
begin
insert('0',c,0);
delete(c,17,1);
if a[i]='1' then SUM(b,c);
end;
if (a[1]='1')and(b1[1]='1') then
begin
SWAP(a);
SWAP(b1);
sum(a,b1);
SUM(b1,c);
end
else if (a[1]='1')or(b1[1]='1') then
begin
if a[1]='1' then a:=b1;
swap(a);
SUM(a,c);
end;
writeln(c);
end
else writeln('FATTAL ERROR');
readkey;
end.