program converter;
var
num,char,base:string;
i,char1,index,a,counter,mod1,sum3,sum2:integer;
sum,hezka:longint;
sum1:real;
st: array of string;
procedure ToDecimal;
begin
if base<>'Decimal' then
begin
for i:= length(num) downto 1 do
begin
char:=copy (num,i,1);
if (char='a') or (char='A') then
begin
char:='10';
end;
if (char='b') or (char='B') then
begin
char:='11';
end;
if (char='c') or (char='C') then
begin
char:='12';
end;
if (char='d') or (char='D') then
begin
char:='13';
end;
if (char='e') or (char='E') then
begin
char:='14';
end;
if (char='f') or (char='F') then
begin
char:='15';
end;
val(char,char1,Index);
sum:=sum + (char1*hezka);
if base='Hexa' then
begin
hezka:=hezka * 16;
end;
if base='Binary' then
begin
hezka:=hezka * 2;
end;
if base='Octal' then
begin
hezka:=hezka * 8;
end;
end;
writeln('the num: ',num,' in decimal is: ',sum);
end;
end;
procedure ToHexa;
begin
if base<>'Hexa' then
begin
a:=0;
counter:=0;
val(num,sum3,Index);
if base='decimal' then
begin
sum1:=sum3;
sum2:=sum3;
end
else
begin
sum1:=sum;
sum2:=sum;
end;
repeat
mod1:=sum2 mod 16;
if mod1=1 then
st:='1';
if mod1=2 then
st:='2';
if mod1=3 then
st:='3';
if mod1=4 then
st:='4';
if mod1=5 then
st:='5';
if mod1=6 then
st:='6';
if mod1=7 then
st:='7';
if mod1=8 then
st:='8';
if mod1=9 then
st:='9';
if mod1=10 then
st:='A';
if mod1=11 then
st:='B';
if mod1=12 then
st:='C';
if mod1=13 then
st:='D';
if mod1=14 then
st:='E';
if mod1=15 then
st:='F';
sum1:=sum1/16;
a:=a+1;
counter:=counter+1;
until (sum1=0) or (sum2=0);
for i:=counter downto 1 do
begin
Writeln('The num in Hexa is:');
Write(St);
end;
end;
end;
begin
hezka:=1;
sum:=0;
writeln('Choose from wich base you want to convert:');
writeln('Binary');
writeln('Octal');
writeln('Hexa');
writeln('Decimal');
readln(base);
writeln('type a num:');
readln(num);
ToDecimal;
readln;
end.