745 / Л.Р.№3 / Lab3_var_1

uses crt;
var A1,A2,D,S:string;
i:word;

procedure checking(A1,A2:string);
var i:word;
begin
i:=0;
repeat
inc(i);
if (length(A1)<>8) or (length(A2)<>8) or
((A1[i] <> '0') and (A1[i] <> '1')) or
((A2[i] <> '0') and (A2[i] <> '1'))
then
begin
writeln('Wrong number!');
writeln('Try again!');
writeln;
write('Write your first number - ');readln(A1);
write('Write your second number - ');readln(A2);
i:=0;
end;
until (i>=length(A1)) or (i>=length(A2));
end;

function sym(var D:string;A1:string;k:word):string;
var f:boolean;
j:integer;
S:string;
begin
S:='';
f:=false;
for j:=k downto 1 do
begin
if f=true
then
if (A1[j]='1') and (D[j]='1')
then
begin
S:=concat('1',S);
f:=true;
end
else
if (A1[j]='0') and (D[j]='0')
then
begin
S:=concat('1',S);
f:=false;
end
else
begin
S:=concat('0',S);
f:=true;
end
else
if (A1[j]='1') and (D[j]='1')
then
begin
S:=concat('0',S);
f:=true;
end
else
if (A1[j]='0') and (D[j]='0')
then
begin
S:=concat('0',S);
f:=false;
end
else
begin
S:=concat('1',S);
f:=false;
end;
end;
if f=true
then S:=concat('1',S);
sym:=S;
end;

procedure DK_PR(var S:string);
var j,i:integer;
begin
j:=length(S);
if S[1]='1'
then
begin
S[1]:='0';
while (S[j]='0') and (j>=1) do dec(j);
for i:=2 to 8 do
if i<j
then
if S[i]='1'
then S[i]:='0'
else S[i]:='1';
end;
end;

procedure PR_DK(var S:string);
var i,j:word;
begin
j:=length(S);
while (S[j]='0') and (j>=1) do dec(j);
for i:=1 to 8 do
if i<j
then
if S[i]='1'
then S[i]:='0'
else S[i]:='1';
end;

procedure PSDob(A1,A2:string);
var i:word;
begin
A1:=concat(A1,'00000000');
D:='0000000000000000';
for i:=1 to 8 do
begin
delete(A1,16,1);
A1:=concat('0',A1);
if A2[i] = '1'
then D:=sym(D,A1,16);
end;
end;

procedure Result(A1,A2:string);
begin
if (A1[1]='0') and (A2[1]='0')
then writeln('Result - ',D)
else
if (A1[1]='1') and (A2[1]='1')
then
begin
DK_PR(A1);
DK_PR(a2);
S:=sym(A1,A2,8);
S:=concat(S,'00000000');
S:=sym(D,S,16);
Delete(S,1,1);
writeln('Result - ',S);
end
else
if (A1[1]='1') and (A2[1]='0')
then
begin
PR_DK(A2);
A2:=concat(A2,'00000000');
S:=sym(D,A2,16);
writeln('Result - ',S);
end
else
begin
PR_DK(A1);
A1:=concat(A1,'00000000');
S:=sym(D,A1,16);
writeln('Result - ',S);
end;
end;

begin
clrscr;
write('Write your first number - ');readln(A1);
write('Write your second number - ');readln(A2);
checking(A1,A2);
PSDob(A1,A2);
Result(A1,A2);
readkey;
end.