Palindrome program

[jimJohnson123]

I am just finishing this palindrome program but I keep getting the error..."file not given" and I believe the error is in this line but cannot be sure...

#include <windows.h>
#include <iostream>
#include <string>
#include <list>
using namespace std;

//MAIN FUNCTION
int main(int argc, char *argv[]){

	HANDLE readFile, writeFile;
	HANDLE readFileMap, writeFileMap;
	PVOID pvreadFile, pvwriteFile;
	DWORD readFileSize;
	string word = "";
	list<string> words;

	//VERIFYING ARGUMENTS
	if(argc>1)
	{
		readFile = CreateFile(argv[1], GENERIC_READ, 0, NULL, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, NULL);

		//IF STATEMENT TO CHECK IF THE READ FILE IS NOT VALID
		if(readFile == INVALID_HANDLE_VALUE)
		{
			//DISPLAY ERROR MESSAGE
			std::cout << "Read file could not be opened." << std::endl;
			return(FALSE);
		}

		readFileMap = CreateFileMapping(readFile, NULL, PAGE_READONLY, 0, 0, NULL);

		//IF STATEMENT TO SEE IF THE READFILEMAP IS NULL
		if(readFileMap == NULL)
		{
			//DISPLAY ERROR MESSAGE
			std::cout << "Read file map could not be opened." << std::endl;
			CloseHandle(readFile);
			return(FALSE);
		}

		pvreadFile = MapViewOfFile(readFileMap, FILE_MAP_READ, 0, 0, 0);

		//IF STATEMENT TO DETERMINE IF PVREADFILE IS NULL
		if(pvreadFile == NULL)
		{
			//DISPLAY ERROR MESSAGE
			std::cout << "Could not map view of read file." << std::endl;
			CloseHandle(readFileMap);
			CloseHandle(readFile);
			return(FALSE);
		}

		//DETERMINE SIZE LIMIT OF INPUT FILE
		readFileSize = GetFileSize(readFile, NULL);

		//writeFile = CreateFile(argv[2], GENERIC_READ | GENERIC_WRITE, 0, NULL, CREATE_NEW, FILE_ATTRIBUTE_NORMAL, NULL);
		writeFile = CreateFile(argv[2], GENERIC_WRITE, 0, NULL, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, NULL);

		//IF STATEMENT TO DETERMINE IF WRITE FILE IS VALID OR NOT
		if(writeFile == INVALID_HANDLE_VALUE)
		{
			//DISPLAY ERROR MESSSAGE IF FILE CAN'T BE OPENED
			std::cout << "Write file could not be opened." << std::endl;
			//std::cout << "argv[1] = " << argv[1] << " argv[2] = " << argv[2] << std::endl;
			UnmapViewOfFile(pvreadFile);
			CloseHandle(readFileMap);
			CloseHandle(readFile);
			return(FALSE);
		}

		writeFileMap = CreateFileMapping(writeFile, NULL, PAGE_READWRITE, 0, readFileSize, NULL);

		//IF STATEMENT TO DETERMINE IF WRITE FILE MAP IS NULL
		if(writeFileMap == NULL)
		{
			//DISPLAY ERROR MESSAGE THAT THE WRITE FILE CANNOT BE MAPPED
			std::cout << "Write File could not be mapped." << std::endl;
			CloseHandle(writeFile);
			UnmapViewOfFile(pvreadFile);
			CloseHandle(readFileMap);
			CloseHandle(readFile);
			return(FALSE);
		}

		pvwriteFile = MapViewOfFile(writeFileMap, FILE_MAP_WRITE, 0,0,0);

		//IF STATEMENT IF THE PVWRITEFILE IS NULL
		if(pvwriteFile == NULL)
		{
			//DISPLAY ERROR MESSAGE THAT I COULD NOT OPEN MAP VIEW OF WRITE FILE
			std::cout << "Could not open map view of write file." << std::endl;
		}

		//POINTERS NEED TO BE CREATED
		PSTR readptr = (PSTR) pvreadFile;
		PSTR writeptr = (PSTR) pvwriteFile;

		//INPUT WORDS FROM FILE WITH FOR STATEMENT
		for(int i=0; i < readFileSize; i++)
		{
			while(isalpha(readptr[i]))
			{
				word = word += tolower(readptr[i]);
				i++;
			};
			words.push_front(word);
			word = "";
		}

		//SORT OUT THE WORDS
		words.sort();

		//WRITE THE WORDS THAT ARE SORTED TO THE OUTPUT FILE AND USE A FOR STATEMENT
		for(int i=0; i<readFileSize; i++)
		{
			word = words.front();
			int j = 0;

			//CREATE WHILE STATEMENT
			while(j < word.size())
			{
				writeptr[i] = word[j];
				j++;
				i++;
			};
			writeptr[i] = ' ';
			words.pop_front();
		}

		//CLEANUP THE FILE
		UnmapViewOfFile(pvwriteFile);
		UnmapViewOfFile(pvreadFile);
		CloseHandle(writeFileMap);
		CloseHandle(readFileMap);
		CloseHandle(writeFile);
		CloseHandle(readFile);
	}
	//ELSE STATEMENT IF CANNOT FIND FILE
	else 
		//DISPLAY ERROR MESSAGE THAT NO FILE IS GIVEN
		cout << "No file given" << endl << endl;

	//RETURN A VALUE
	return 0;
}

[jimJohnson123]

and Sorry about the code tags will need someone to show how to put them in for this site as well

[Paul McKenzie]

and Sorry about the code tags will need someone to show how to put them in for this site as well

The ending code tag must be [/code].

Second, for a palindrome program, you sure are doing a lot of non-palindrome related things, such as opening and closing files. As a matter of fact, where is the "palindrome" code in this program?

Regards,

Paul McKenzie

[Paul McKenzie]

I am just finishing this palindrome program but I keep getting the error..."file not given" and I believe the error is in this line but cannot be sure...

Use your debugger.

You keep getting that error because the logic flow of your program goes to that line. If you want to figure out why the logic goes to that line, debug the program and single step through it.

Regards,

Paul McKenzie

[jimJohnson123]

I know I am but it is required to use memory mapping (why I dont have the slightest idea but it is what he wants to see)

Here is the palindrome section which should work...

		//INPUT WORDS FROM FILE WITH FOR STATEMENT
		for(int i=0; i < readFileSize; i++)
		{
			while(isalpha(readptr[i]))
			{
				word = word += tolower(readptr[i]);
				i++;
			};
			words.push_front(word);
			word = "";
		}

		//SORT OUT THE WORDS
		words.sort();

		//WRITE THE WORDS THAT ARE SORTED TO THE OUTPUT FILE AND USE A FOR STATEMENT
		for(int i=0; i<readFileSize; i++)
		{
			word = words.front();
			int j = 0;

			//CREATE WHILE STATEMENT
			while(j < word.size())
			{
				writeptr[i] = word[j];
				j++;
				i++;
			};
			writeptr[i] = ' ';
			words.pop_front();
		}

		//CLEANUP THE FILE
		UnmapViewOfFile(pvwriteFile);
		UnmapViewOfFile(pvreadFile);
		CloseHandle(writeFileMap);
		CloseHandle(readFileMap);
		CloseHandle(writeFile);
		CloseHandle(readFile);
	}

[Paul McKenzie]

Here is the palindrome section which should work...

Seriously, I see nothing in that code that indicates "palindrome". I see no code checking if a string forward is the same reversed.

That's why functions are important in a program. No one would know what that block of code is supposed to do.

#include <string>
#include <algorithm>

bool isPalindrome(const std::string& s)
{
    std::string sReverse = s;
    std::reverse(sReverse.begin(), sReverse.end());
    return s == sReverse;  // return true if the reverse is the same as non-reverse
}

int main()
{
    bool ret = isPalindrome( "eve redivider" );
}

That program and function above is a very strict palindrome checker (it takes in consideration everything -- casing, white space, punctuation, etc.). If it's too strict, then you rewrite it to be less strict.

Regards,

Paul McKenzie

[romil797]

Paul McKenzie is right

[jimJohnson123]

How about this for my palindrome code...

 // Strart of Palindrome Catcher.
	  char compare;
	  bool drome = false;
	  char tmpArray [600];
	  char tmpOutArray [600];
	  int incount = 0;
	  int outcount = dwOutFileSize;
	  int t = 0;
	  stack<char> stack;  //Useing #stack
	  queue<char> queue;

	  // read the values of the memory-mapped file
      // from start to finish placing values in
      //array
//-----------------------------------------	  
	 for (i = 0; i < dwInFileSize; i++) 
    {
		InFileptr[i];
	 }
	  for (i = 0; i < dwInFileSize; i++) 
    {
		stack.push(tmpArray[i]);
	 }


			//If a space is not found push all chars onto array & increase the input count	
		if (InFileptr[i] != ' ') 
		{
			stack.push(tmpArray[i]);
			queue.push(tmpOutArray[i]);
		//test for output ----------------
		//	stack.push(outFileMap[i]);
		//----------------------------------
			incount++;	
		}
   //If a space is found compare chars one by one with the same word in reverse 
		if (InFileptr[i] == ' ')
		{
			while (!stack.empty())
			{
					stack.top() = tmpArray[t];
					t ++;
					stack.pop() ;
					cout << "top:" << stack.top()<< endl;

					outcount --;
					int i = 0;


		//while (!stack.empty())
		//	if (tmpArray[t] != stack.pop()) return false;
		//	return true;
					//if (compare == InFileptr[i]);
					//{

					//}

				}
				
		}
	  }

	  //Cleanup
	  UnmapViewOfFile(pvInFile);
      CloseHandle(inFileMap);
      CloseHandle(inFile);
      UnmapViewOfFile(outFile);
      CloseHandle(outFileMap);
      CloseHandle(outFile);
}

[Paul McKenzie]

How about this for my palindrome code...

Compare that code with what I wrote. Which one looks easier and more organized? I wrote a palindrome checker in 3 lines of code.

Regardless of where the input comes from, I would have expected that you create a string -- how you create that string doesn't matter. Then once that string is created, you check if that string is a palindrome.

Regards,

Paul McKenzie

[jimJohnson123]

Yours look much better and orgnized but I guess it just looks too simple unless Im really overthinking this

[Paul McKenzie]

Yours look much better and orgnized but I guess it just looks too simple unless Im really overthinking this

1) Create the string.
2) Check if string is a palindrome

int main()
{
     std::string s = GetMyStringFromMemoryMappedFile( );
     if ( isPalindrome( s ) )
     {
        cout << s << " is a palindrome";
     }
}

Isn't this all it boils down to?

Regards,

Paul McKenzie