Output problem

[Protoman]

My code keeps putting the input statements on the same line, instead of
letting me input them normally; here's the code:

int main()
{
cout << "Encrypt or decrypt?[1=encrypt|0=dec rypt] ";
bool select;
cin >> select;
if(select==true )
{
string cleartext;
string key;
cout << "Enter the cleartext: " << endl;
getline(cin,cle artext,'\n');
cout << "Enter the key: " << endl;
getline(cin,key ,'\n');
string ciphertext(encr ypt(cleartext,k ey));
cout << "Ciphertext : " << ciphertext << endl;
}
string ciphertext;
string key;
cout << "Enter the ciphertext: ";
getline(cin,cip hertext,'\n');
cout << "Enter the key: ";
getline(cin,key ,'\n');
string decrypted(decry pt(ciphertext,k ey));
cout << "Cleartext: " << decrypted << endl;
system("PAUSE") ;
return EXIT_SUCCESS;
}

Can you help me? Thanks.

[John Harrison]

Re: Output problem

Protoman wrote:[color=blue]
> My code keeps putting the input statements on the same line, instead of
> letting me input them normally; here's the code:
>
> int main()
> {
> cout << "Encrypt or decrypt?[1=encrypt|0=dec rypt] ";
> bool select;
> cin >> select;
> if(select==true )
> {
> string cleartext;
> string key;
> cout << "Enter the cleartext: " << endl;
> getline(cin,cle artext,'\n');
> cout << "Enter the key: " << endl;
> getline(cin,key ,'\n');
> string ciphertext(encr ypt(cleartext,k ey));
> cout << "Ciphertext : " << ciphertext << endl;
> }
> string ciphertext;
> string key;
> cout << "Enter the ciphertext: ";
> getline(cin,cip hertext,'\n');
> cout << "Enter the key: ";
> getline(cin,key ,'\n');
> string decrypted(decry pt(ciphertext,k ey));
> cout << "Cleartext: " << decrypted << endl;
> system("PAUSE") ;
> return EXIT_SUCCESS;
> }
>
> Can you help me? Thanks.
>[/color]

I'm not completely sure I follow you but I think the problem is this

cin >> select;

followed by this

getline(cin,cle artext,'\n');

(BTW you don't need to put '\n', it is the default).

Think carefully about what the two statements do. The first reads a
boolean value but does not read the newline character. Even though you
have typed a newline character (i.e. the enter key) it has not been read
yet. Then you get to the getline statement, that reads upto the next
newline. Well the next newline character is the one you typed after
entering the boolean value, which is not what you want.

The answer is to tell C++ to ignore the newline character after the
boolean value. You do that with this strange code

cin >> select;
cin.ignore(INT_ MAX, '\n');
....
getline(cin,cle artext);

You need to include <limits.h> to get INT_MAX defined.

This should be a FAQ but it doesn't seem to be.

john

[Protoman]

Re: Output problem

OK, but now it doesn't show the string "decrypted" .

[Neelesh]

Re: Output problem


John Harrison wrote:[color=blue]
> The answer is to tell C++ to ignore the newline character after the
> boolean value. You do that with this strange code
>
> cin >> select;
> cin.ignore(INT_ MAX, '\n');[/color]

you can also use
cin.ignore(1);
since it is only one newline character which you want to ignore.
[color=blue]
> ...
> getline(cin,cle artext);
>
> You need to include <limits.h> to get INT_MAX defined.
>[/color]
Prefer <climits>. Still better, include <limits> and use
std::numeric_li mits<int>::max( );

[John Harrison]

Re: Output problem

Protoman wrote:[color=blue]
> OK, but now it doesn't show the string "decrypted" .
>[/color]

You mean that when you execute

cout << "Cleartext: " << decrypted << endl;

nothing appears on the screen?

I don't know why that would be.

This might be a case where it would help to post a complete program. You
could replace encrypt with a dummy function (e.g.)

string encrypt(string x, string y)
{
return x;
}

and then post all the rest of the code.

john

[John Harrison]

Re: Output problem

Neelesh wrote:[color=blue]
> John Harrison wrote:
>[color=green]
>>The answer is to tell C++ to ignore the newline character after the
>>boolean value. You do that with this strange code
>>
>>cin >> select;
>>cin.ignore(IN T_MAX, '\n');[/color]
>
>
> you can also use
> cin.ignore(1);
> since it is only one newline character which you want to ignore.
>[/color]

What if the user has typed a space between the boolean and the newline?
[color=blue]
>[color=green]
>>...
>>getline(cin,c leartext);
>>
>>You need to include <limits.h> to get INT_MAX defined.
>>[/color]
>
> Prefer <climits>. Still better, include <limits> and use
> std::numeric_li mits<int>::max( );
>[/color]

Why is that better?

john

[Protoman]

Re: Output problem

OK, here's the rest:

#ifndef VIGENERE_HPP
#define VIGENERE_HPP
#include <iostream>
#include <algorithm>
#include <cstdlib>
#include <cctype>
#include <string>
using namespace std;

namespace
{
const char vTable[26][27]=
{
{'A','B','C','D ','E','F','G',' H','I','J','K', 'L','M','N','O' ,'P','Q','R','S ','T','U','V',' W','X','Y','Z', '\0'},

{'B','C','D','E ','F','G','H',' I','J','K','L', 'M','N','O','P' ,'Q','R','S','T ','U','V','W',' X','Y','Z','A', '\0'},

{'C','D','E','F ','G','H','I',' J','K','L','M', 'N','O','P','Q' ,'R','S','T','U ','V','W','X',' Y','Z','A','B', '\0'},

{'D','E','F','G ','H','I','J',' K','L','M','N', 'O','P','Q','R' ,'S','T','U','V ','W','X','Y',' Z','A','B','C', '\0'},

{'E','F','G','H ','I','J','K',' L','M','N','O', 'P','Q','R','S' ,'T','U','V','W ','X','Y','Z',' A','B','C','D', '\0'},

{'F','G','H','I ','J','K','L',' M','N','O','P', 'Q','R','S','T' ,'U','V','W','X ','Y','Z','A',' B','C','D','E', '\0'},

{'G','H','I','J ','K','L','M',' N','O','P','Q', 'R','S','T','U' ,'V','W','X','Y ','Z','A','B',' C','D','E','F', '\0'},

{'H','I','J','K ','L','M','N',' O','P','Q','R', 'S','T','U','V' ,'W','X','Y','Z ','A','B','C',' D','E','F','G', '\0'},

{'I','J','K','L ','M','N','O',' P','Q','R','S', 'T','U','V','W' ,'X','Y','Z','A ','B','C','D',' E','F','G','H', '\0'},

{'J','K','L','M ','N','O','P',' Q','R','S','T', 'U','V','W','X' ,'Y','Z','A','B ','C','D','E',' F','G','H','I', '\0'},

{'K','L','M','N ','O','P','Q',' R','S','T','U', 'V','W','X','Y' ,'Z','A','B','C ','D','E','F',' G','H','I','J', '\0'},

{'L','M','N','O ','P','Q','R',' S','T','U','V', 'W','X','Y','Z' ,'A','B','C','D ','E','F','G',' H','I','J','K', '\0'},

{'M','N','O','P ','Q','R','S',' T','U','V','W', 'X','Y','Z','A' ,'B','C','D','E ','F','G','H',' I','J','K','L', '\0'},

{'N','O','P','Q ','R','S','T',' U','V','W','X', 'Y','Z','A','B' ,'C','D','E','F ','G','H','I',' J','K','L','M', '\0'},

{'O','P','Q','R ','S','T','U',' V','W','X','Y', 'Z','A','B','C' ,'D','E','F','G ','H','I','J',' K','L','M','N', '\0'},

{'P','Q','R','S ','T','U','V',' W','X','Y','Z', 'A','B','C','D' ,'E','F','G','H ','I','J','K',' L','M','N','O', '\0'},

{'Q','R','S','T ','U','V','W',' X','Y','Z','A', 'B','C','D','E' ,'F','G','H','I ','J','K','L',' M','N','O','P', '\0'},

{'R','S','T','U ','V','W','X',' Y','Z','A','B', 'C','D','E','F' ,'G','H','I','J ','K','L','M',' N','O','P','Q', '\0'},

{'S','T','U','V ','W','X','Y',' Z','A','B','C', 'D','E','F','G' ,'H','I','J','K ','L','M','N',' O','P','Q','R', '\0'},

{'T','U','V','W ','X','Y','Z',' A','B','C','D', 'E','F','G','H' ,'I','J','K','L ','M','N','O',' P','Q','R','S', '\0'},

{'U','V','W','X ','Y','Z','A',' B','C','D','E', 'F','G','H','I' ,'J','K','L','M ','N','O','P',' Q','R','S','T', '\0'},

{'V','W','X','Y ','Z','A','B',' C','D','E','F', 'G','H','I','J' ,'K','L','M','N ','O','P','Q',' R','S','T','U', '\0'},

{'W','X','Y','Z ','A','B','C',' D','E','F','G', 'H','I','J','K' ,'L','M','N','O ','P','Q','R',' S','T','U','V', '\0'},

{'X','Y','Z','A ','B','C','D',' E','F','G','H', 'I','J','K','L' ,'M','N','O','P ','Q','R','S',' T','U','V','W', '\0'},

{'Y','Z','A','B ','C','D','E',' F','G','H','I', 'J','K','L','M' ,'N','O','P','Q ','R','S','T',' U','V','W','X', '\0'},

{'Z','A','B','C ','D','E','F',' G','H','I','J', 'K','L','M','N' ,'O','P','Q','R ','S','T','U',' V','W','X','Y', '\0'},

};

string encrypt(const string& cleartext,const string& key)
{
string encrypted;
for(int i=0;i<cleartext .length();i++)
encrypted+=vTab le[cleartext[i]-'A'][key[i%key.length()]-'A'];
return encrypted;
}
}

string decrypt(const string& ciphertext, const string& key)
{
string decrypted;
for (int i=0;i<ciphertex t.length();i++)
for (char j=0;j<27;j++)
{
if (vTable[j][key[i%key.length()]-'A']==ciphertext[i])
{
decrypted+=stat ic_cast<char>(j +'A');
break;
}
}
return decrypted;
}
#endif

[Protoman]

Re: Output problem

OK, but now it doesn't show the string "decrypted" .

[Protoman]

Re: Output problem

Here's the rest:

#ifndef VIGENERE_HPP
#define VIGENERE_HPP
#include <iostream>
#include <algorithm>
#include <cstdlib>
#include <cctype>
#include <string>
using namespace std;

namespace
{
const char vTable[26][27]=
{
{'A','B','C','D ','E','F','G',' H','I','J','K', 'L','M','N','O' ,'P','Q','R','S ','T','U','V',' W','X','Y','Z', '\0'},

{'B','C','D','E ','F','G','H',' I','J','K','L', 'M','N','O','P' ,'Q','R','S','T ','U','V','W',' X','Y','Z','A', '\0'},

{'C','D','E','F ','G','H','I',' J','K','L','M', 'N','O','P','Q' ,'R','S','T','U ','V','W','X',' Y','Z','A','B', '\0'},

{'D','E','F','G ','H','I','J',' K','L','M','N', 'O','P','Q','R' ,'S','T','U','V ','W','X','Y',' Z','A','B','C', '\0'},

{'E','F','G','H ','I','J','K',' L','M','N','O', 'P','Q','R','S' ,'T','U','V','W ','X','Y','Z',' A','B','C','D', '\0'},

{'F','G','H','I ','J','K','L',' M','N','O','P', 'Q','R','S','T' ,'U','V','W','X ','Y','Z','A',' B','C','D','E', '\0'},

{'G','H','I','J ','K','L','M',' N','O','P','Q', 'R','S','T','U' ,'V','W','X','Y ','Z','A','B',' C','D','E','F', '\0'},

{'H','I','J','K ','L','M','N',' O','P','Q','R', 'S','T','U','V' ,'W','X','Y','Z ','A','B','C',' D','E','F','G', '\0'},

{'I','J','K','L ','M','N','O',' P','Q','R','S', 'T','U','V','W' ,'X','Y','Z','A ','B','C','D',' E','F','G','H', '\0'},

{'J','K','L','M ','N','O','P',' Q','R','S','T', 'U','V','W','X' ,'Y','Z','A','B ','C','D','E',' F','G','H','I', '\0'},

{'K','L','M','N ','O','P','Q',' R','S','T','U', 'V','W','X','Y' ,'Z','A','B','C ','D','E','F',' G','H','I','J', '\0'},

{'L','M','N','O ','P','Q','R',' S','T','U','V', 'W','X','Y','Z' ,'A','B','C','D ','E','F','G',' H','I','J','K', '\0'},

{'M','N','O','P ','Q','R','S',' T','U','V','W', 'X','Y','Z','A' ,'B','C','D','E ','F','G','H',' I','J','K','L', '\0'},

{'N','O','P','Q ','R','S','T',' U','V','W','X', 'Y','Z','A','B' ,'C','D','E','F ','G','H','I',' J','K','L','M', '\0'},

{'O','P','Q','R ','S','T','U',' V','W','X','Y', 'Z','A','B','C' ,'D','E','F','G ','H','I','J',' K','L','M','N', '\0'},

{'P','Q','R','S ','T','U','V',' W','X','Y','Z', 'A','B','C','D' ,'E','F','G','H ','I','J','K',' L','M','N','O', '\0'},

{'Q','R','S','T ','U','V','W',' X','Y','Z','A', 'B','C','D','E' ,'F','G','H','I ','J','K','L',' M','N','O','P', '\0'},

{'R','S','T','U ','V','W','X',' Y','Z','A','B', 'C','D','E','F' ,'G','H','I','J ','K','L','M',' N','O','P','Q', '\0'},

{'S','T','U','V ','W','X','Y',' Z','A','B','C', 'D','E','F','G' ,'H','I','J','K ','L','M','N',' O','P','Q','R', '\0'},

{'T','U','V','W ','X','Y','Z',' A','B','C','D', 'E','F','G','H' ,'I','J','K','L ','M','N','O',' P','Q','R','S', '\0'},

{'U','V','W','X ','Y','Z','A',' B','C','D','E', 'F','G','H','I' ,'J','K','L','M ','N','O','P',' Q','R','S','T', '\0'},

{'V','W','X','Y ','Z','A','B',' C','D','E','F', 'G','H','I','J' ,'K','L','M','N ','O','P','Q',' R','S','T','U', '\0'},

{'W','X','Y','Z ','A','B','C',' D','E','F','G', 'H','I','J','K' ,'L','M','N','O ','P','Q','R',' S','T','U','V', '\0'},

{'X','Y','Z','A ','B','C','D',' E','F','G','H', 'I','J','K','L' ,'M','N','O','P ','Q','R','S',' T','U','V','W', '\0'},

{'Y','Z','A','B ','C','D','E',' F','G','H','I', 'J','K','L','M' ,'N','O','P','Q ','R','S','T',' U','V','W','X', '\0'},

{'Z','A','B','C ','D','E','F',' G','H','I','J', 'K','L','M','N' ,'O','P','Q','R ','S','T','U',' V','W','X','Y', '\0'},

};

string encrypt(const string& cleartext,const string& key)
{
string encrypted;
for(int i=0;i<cleartext .length();i++)
encrypted+=vTab le[cleartext[i]-'A'][key[i%key.length()]-'A'];
return encrypted;
}
}

string decrypt(const string& ciphertext, const string& key)
{
string decrypted;
for (int i=0;i<ciphertex t.length();i++)
for (char j=0;j<27;j++)
{
if (vTable[j][key[i%key.length()]-'A']==ciphertext[i])
{
decrypted+=stat ic_cast<char>(j +'A');
break;
}
}
return decrypted;
}
#endif

[Neelesh]

Re: Output problem

John Harrison wrote:[color=blue]
> Neelesh wrote:[color=green]
> > John Harrison wrote:
> >[color=darkred]
> >>The answer is to tell C++ to ignore the newline character after the
> >>boolean value. You do that with this strange code
> >>
> >>cin >> select;
> >>cin.ignore(IN T_MAX, '\n');[/color]
> >
> >
> > you can also use
> > cin.ignore(1);
> > since it is only one newline character which you want to ignore.[/color][/color]
[color=blue][color=green]
> >[/color]
>
> What if the user has typed a space between the boolean and the newline?[/color]

Yes, we will need your version in that case. I was assuming that user
will simply hit return after the boolean.
[color=blue]
>[color=green]
> >[color=darkred]
> >>...
> >>getline(cin,c leartext);
> >>
> >>You need to include <limits.h> to get INT_MAX defined.
> >>[/color]
> >
> > Prefer <climits>. Still better, include <limits> and use
> > std::numeric_li mits<int>::max( );
> >[/color]
>
> Why is that better?[/color]

I am not saying that the previous one will not work. But from what I
have read at various places on net and in various books is that
<climits> or <limits> is specifically designed for usage with C++ (for
defining implementation dependent limits) - may be because it puts the
names in a namespace and doesnot pollute the global namespace. Please
correct me if I am wrong.

[Neil Cerutti]

Re: Output problem

On 2005-11-11, Neelesh <neelesh.bodas@ gmail.com> wrote:[color=blue]
>
> John Harrison wrote:[color=green]
>> The answer is to tell C++ to ignore the newline character after the
>> boolean value. You do that with this strange code
>>
>> cin >> select;
>> cin.ignore(INT_ MAX, '\n');[/color]
>
> you can also use
> cin.ignore(1);
> since it is only one newline character which you want to ignore.
>[color=green]
>> ...
>> getline(cin,cle artext);
>>
>> You need to include <limits.h> to get INT_MAX defined.
>>[/color]
> Prefer <climits>. Still better, include <limits> and use
> std::numeric_li mits<int>::max( );[/color]

Or, even more specifically:

std::numeric_li mits<streamsize >::max();

--
Neil Cerutti

[Karl Heinz Buchegger]

Re: Output problem

Protoman wrote:[color=blue]
>
> OK, but now it doesn't show the string "decrypted" .[/color]

Fire up your debugger, step through the code and watch
as the variables change.

That's what the I do, what all programmers around me do, probably
what most programmers around the world do.

Should be good enough for you also :-)

--
Karl Heinz Buchegger
kbuchegg@gascad .at

[John Harrison]

Re: Output problem

Protoman wrote:[color=blue]
> Here's the rest:
>[/color]

I ran your code. It worked for me provided I remembered to enter
uppercase text.

john

[Mike Wahler]

Re: Output problem


"Neelesh" <neelesh.bodas@ gmail.com> wrote in message
news:1131699928 .586887.159060@ o13g2000cwo.goo glegroups.com.. .
[color=blue]
> I was assuming that user[/color]

Such an attitude is the source of uncountable bugs.

-Mike

[Howard]

Re: Output problem


"Protoman" <Protoman2050@g mail.com> wrote in message
news:1131697014 .799837.315880@ o13g2000cwo.goo glegroups.com.. .[color=blue]
> OK, but now it doesn't show the string "decrypted" .
>[/color]

Still haven't learned to quote what you're responding to?

-Howard