Cheat Engine :: View topic - c++ iterator help

Cheat Engine Forum Index

Cheat Engine
The Official Site of Cheat Engine

FAQ

Usergroups

Register

Log in to check your private messages

c++ iterator help

Cheat Engine Forum Index -> General programming

View previous topic :: View next topic

Author

Message

AverageAzn247
Grandmaster Cheater

Reputation: 34

Joined: 01 Oct 2007
Posts: 909
Location: Austin,TX with 72 virgins

Posted: Mon Dec 05, 2011 5:39 pm Post subject: c++ iterator help

Reply with quote

this is supposed to detect if it was a palindrome or not. Anyone know how i can fix it? Trying to return false if it fails to meet the conditions.
bool is_pal(string input)
{
bool check=true;
string::iterator first= input.begin();
string::reverse_iterator last=input.rbegin();
while( *(first++) == *(last++) && first != input.end() )
{
check = false;

}
return check;

}
_________________

Waxxup wrote:

What are Night Elves?
A girl group?

Send private message

MSN Messenger

atom0s
Moderator

Reputation: 205

Joined: 25 Jan 2006
Posts: 8587
Location: 127.0.0.1

Posted: Mon Dec 05, 2011 6:58 pm Post subject:

Reply with quote

Something like this should work:

Code:

bool is_pal(string input)
{
std::string::iterator first = input.begin();
std::string::iterator last = input.end();
std::string::reverse_iterator rlast = input.rbegin();

for( first; first != last; ++first, ++rlast )
{
if( *first != *rlast )
return false;
}

return true;
}

Assuming you are just doing single words like 'racecar' without punctuation and such.
_________________

- Retired.

Send private message

Visit poster's website

AverageAzn247
Grandmaster Cheater

Reputation: 34

Joined: 01 Oct 2007
Posts: 909
Location: Austin,TX with 72 virgins

Posted: Mon Dec 05, 2011 7:25 pm Post subject:

Reply with quote

Wiccaan wrote:

Something like this should work:

Code:

bool is_pal(string input)
{
std::string::iterator first = input.begin();
std::string::iterator last = input.end();
std::string::reverse_iterator rlast = input.rbegin();

for( first; first != last; ++first, ++rlast )
{
if( *first != *rlast )
return false;
}

return true;
}

Assuming you are just doing single words like 'racecar' without punctuation and such.

i am trying to get it to read a sentence ex "Madam, I'm Adam.". I already removed the punc and white spaces before sending it into is_pal
http://www.mediafire.com/?tstajs5o6arwsoi
_________________

Waxxup wrote:

What are Night Elves?
A girl group?

Send private message

MSN Messenger

atom0s
Moderator

Reputation: 205

Joined: 25 Jan 2006
Posts: 8587
Location: 127.0.0.1

Posted: Mon Dec 05, 2011 8:04 pm Post subject:

Reply with quote

You need to convert the text to lowercase as well before you compare it.

Code:

bool is_pal( const std::string& str )
{
// Convert input to lower-case.
std::string input = str;
std::transform( input.begin(), input.end(), input.begin(), tolower );

std::string::iterator first = input.begin();
std::string::iterator last = input.end();
std::string::reverse_iterator rlast = input.rbegin();

for( first; first != last; ++first, ++rlast )
{
if( *first != *rlast )
return false;
}

return true;
}

Edit : Also note this needs another include:
#include <algorithm>
_________________

- Retired.

Send private message

Visit poster's website

AverageAzn247
Grandmaster Cheater

Reputation: 34

Joined: 01 Oct 2007
Posts: 909
Location: Austin,TX with 72 virgins

Posted: Mon Dec 05, 2011 11:12 pm Post subject:

Reply with quote

Wiccaan wrote:

You need to convert the text to lowercase as well before you compare it.

Code:

bool is_pal( const std::string& str )
{
// Convert input to lower-case.
std::string input = str;
std::transform( input.begin(), input.end(), input.begin(), tolower );

std::string::iterator first = input.begin();
std::string::iterator last = input.end();
std::string::reverse_iterator rlast = input.rbegin();

for( first; first != last; ++first, ++rlast )
{
if( *first != *rlast )
return false;
}

return true;
}

Edit : Also note this needs another include:
#include <algorithm>

i don't think thats the problem because i already had this

Code:

for(int i=0;i<input.length();i++)
{input[i]=tolower(input[i]);}

_________________

Waxxup wrote:

What are Night Elves?
A girl group?

Send private message

MSN Messenger

atom0s
Moderator

Reputation: 205

Joined: 25 Jan 2006
Posts: 8587
Location: 127.0.0.1

Posted: Tue Dec 06, 2011 7:04 am Post subject:

Reply with quote

My implementation of this works with the sentence and word versions based on your original post:

Code:

std::string remove_whitespace( const std::string& str )
{
std::string result;
for( std::string::const_iterator iter = str.begin(), iterend = str.end(); iter != iterend; ++iter )
{
if( *iter != ' ' )
result += *iter;
}
return result;
}

std::string remove_punc( const std::string& str )
{
std::string result;
for( std::string::const_iterator iter = str.begin(), iterend = str.end(); iter != iterend; ++iter )
{
if( ispunct( *iter ) )
result += ' ';
else
result += *iter;
}
return result;
}

bool is_pal( const std::string& str )
{
// Convert input to lower-case.
std::string input = str;
std::transform( input.begin(), input.end(), input.begin(), tolower );

std::string::iterator first = input.begin();
std::string::iterator last = input.end();
std::string::reverse_iterator rlast = input.rbegin();

for( first; first != last; ++first, ++rlast )
{
if( *first != *rlast )
return false;
}

return true;
}

Usage:

Code:

std::string test = remove_punc( std::string( "Madam, I'm Adam." ) );
test = remove_whitespace( test );
bool bTest1 = is_pal( test );
bool bTest2 = is_pal( std::string( "racecar" ) );
bool bTest3 = is_pal( std::string( "herpderp" ) );

Returns:
true
true
false

So looks fine on me end.
_________________

- Retired.

Send private message

Visit poster's website

AverageAzn247
Grandmaster Cheater

Reputation: 34

Joined: 01 Oct 2007
Posts: 909
Location: Austin,TX with 72 virgins

Posted: Wed Dec 07, 2011 1:38 pm Post subject:

Reply with quote

its having problems with white spacing.
Rise to vote, sir.
A Toyota.
are all giving me problems
_________________

Waxxup wrote:

What are Night Elves?
A girl group?

Send private message

MSN Messenger

atom0s
Moderator

Reputation: 205

Joined: 25 Jan 2006
Posts: 8587
Location: 127.0.0.1

Posted: Wed Dec 07, 2011 1:48 pm Post subject:

Reply with quote

AverageAzn247 wrote:

its having problems with white spacing.
Rise to vote, sir.
A Toyota.
are all giving me problems

Be sure you are calling remove_punc and remove_whitespace before you call is_pal in my example above.
Both the two new examples worked fine for me.
_________________

- Retired.

Send private message

Visit poster's website

AverageAzn247
Grandmaster Cheater

Reputation: 34

Joined: 01 Oct 2007
Posts: 909
Location: Austin,TX with 72 virgins

Posted: Wed Dec 07, 2011 2:32 pm Post subject:

Reply with quote

my bad. turns out i was sending the the unedited file to the function
_________________

Waxxup wrote:

What are Night Elves?
A girl group?

Send private message

MSN Messenger

Display posts from previous:

	Cheat Engine Forum Index -> General programming	All times are GMT - 6 Hours
Page 1 of 1

Jump to:

You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum
You cannot attach files in this forum
You can download files in this forum

Powered by phpBB © 2001, 2005 phpBB Group

CE Wiki IRC (#CEF) Twitter
Third party websites