Thread: help me with some idea...

hi everyone ... i am doing the intersection, can someone let me know which intersect with which please... as i am really confuse on the StringSet otherset .. here is my code and class...

which is on red color..

this is my implementation code

Code:

#include "stringset.h"

// insert a value into the set
// Pre: a string value
// Post: the value is inserted into the set if it 
//      is not already present
void StringSet::insert(string value) 
{
     if( !contains(value) )
     {
         contents.push_back(value);
     }
}     

// test for a value
// Pre: a string value
// Post: returns 1 if the value is present in the StringSet, 0 otherwise
int StringSet::contains(string value) 
{
    int loc;
    bool found = false;
    
    for(loc = 0; loc < contents.size(); loc++)
         if(contents[loc] == value)
         {
              found = true;
              break;
         }
    if(found)
         return 1;
    else
         return 0;
  
}
// intersection of this set with another
// Pre: a StringSet object
// Post: returns a new StringSet which is the intersection 
//       of this  with otherset, ie. only the items common to both StringSets
StringSet StringSet::set_intersection(StringSet otherset)
{
          

}

// union of this set with another
// Pre: a StringSet object
// Post: returns a new StringSet which is the union 
//       of this  with otherset, ie. the items in either StringSets
StringSet StringSet::set_union(StringSet otherset)
{
 
}


// print
// Pre: None
// Post: the stringset will be printed to cout
void StringSet::print()
{
     for( int i=0; i<contents.size(); i++ ) 
        cout << "\t" << contents[i] << endl;
}

and this is my mainc.pp

Code:

#include "inverted_index.h"

int main() 
{

  StringSet ss;

  ss.insert("one");
  ss.insert("two");
  ss.insert("three");
  ss.insert("one");
  

  ss.print();
  if ( ss.contains("one") ) 
    cout << "ok - contains('one')\n";
  else
    cout << "fail - contains('one')\n";
/*   
  // test the InvertedIndex 
 InvertedIndex idx;
 idx.tally("cat", "cats.txt");
 idx.tally("cat", "animals.txt");
 idx.tally("cat", "everything.txt");
 idx.tally("dog", "dogs.txt");
 
 idx.print();
  // searching idx for cat should give us three files
  vector <string> query;
  query.push_back("cat");
  StringSet si = idx.search(query);
  if (si.contains("cats.txt") && si.contains("animals.txt") && si.contains("everything.txt") )
    cout << "ok - search('cat')\n";
  else 
    cout << "fail - search('cat')\n";

  if (si.contains("dogs.txt"))
    cout << "fail - search('cat') -- dogs.txt found\n";
  else 
    cout << "ok - search('cat') no dogs\n";

*/ 
  system("PAUSE");
  return 0;
}

this is another implementation which might be helpful ...

Code:

#include "inverted_index.h"
#include "osdir.h"



// InvertedIndex::tally
//   Pre: a word and file pair as strings
//   Post: adds the file to the index under word
 void InvertedIndex::tally(string word, string file) 
{
      storage.push_back(word);
      //storage.push_back(file);
      
      //vector<string>::iterator theIterator = storage.end();
      //storage.insert( theIterator, file );
}

// InvertedIndex::search 
// Pre: a vector of strings as search terms
// Post: a vector of strings being the files that all of the
//      input words occur in in the index.
StringSet InvertedIndex::search(vector <string> words) 
{

}

// print
// Pre: an index structure
// Post: renders the index on the screen
void InvertedIndex::print() 
{
     for(int i = 0; i < storage.size(); i++)
     {
         cout<<endl<<storage[i]<<" ";
     }
     cout<<endl<<endl;
}

//
// These  methods have been written for you, there is no need to change 
// anything below this text.  These methods make use of the other
// methods defined above.
//


// IndexFile
//  Pre: a file name as a string
//  Post: the words in the file are added to the inverted index
void InvertedIndex::indexFile( string filename ) {

	vector <string> words = ReadFile(filename);
	for(int i=0; i<words.size(); i++) {
		tally(words[i], filename);
	}
}

void InvertedIndex::indexDir( string dirname ) {

  string filename; 
  oslink::directory dir(dirname);
  while (dir) {
     filename = dirname + "/" + dir.next();
     indexFile(filename);
  } 
}

The intersection of two sets is the set that contains the elements that are present in both of the two sets. That is, if c is an element in "this" set, then c is in the intersection if and only if otherset.contains(c). So a very basic algorithm could create an empty set to hold the intersection, go through the elements in one of the sets and check if they are in the other one too, and if they are, add them to the intersection set.

can you provide some sample as i am relly newbie on this ... thank you .. and will really appreciated..

i am trying to do it, this is my code.. but please correct for me ..
(anyone)

Code:

StringSet StringSet::set_intersection(StringSet otherset)
{
    stringset result;

    for(int i = 0; i < contents.size(); i++)
        if(otherset.contains(contents[i])
            result = contents[i];  
}

> result = contents[i];

Instead of setting result to contents[i], you want to insert contents[i] to the result. So something like

Code:

result.insert(contents[i]);

will this work??

Code:

StringSet StringSet::set_intersection(StringSet otherset)
{
    stringset result;

    for(int i = 0; i < contents.size(); i++)
        if(otherset.contains(contents[i])
            result.insert(contents[i]);
}

Have you tried it?

Is your class called stringset or StringSet? You use both.

The function is declared to return StringSet but you don't have a "return" statement.

Originally Posted by laserlight

peter_hii, is this homework? If it is not, then you really might want to use what I suggested in your other thread.

the format is unchangeble.. but really appreciate that you done that.. really make sense for me ...
and using set is really easy but i want to stick with my own format......

Originally Posted by peter_hii

L:\assignment 2\stringset.cpp In member function `StringSet StringSet::set_intersection(StringSet)':
56 L:\assignment 2\stringset.cpp expected `)' before "result"
L:\assignment 2\Makefile.win [Build Error] [stringset.o] Error 1

Well, like it says, the compiler is expecting to find a ")" before the word "result" on line 56. It doesn't get plainer than that. You are missing a closing parenthesis.

Originally Posted by laserlight

If that is the case, then use your StringSet class as a wrapper class for std::set<std::string>, instead of making it a typedef.

you mean ??

for the declaration// make it set<string> stringset; ???

Originally Posted by joni

Well, like it says, the compiler is expecting to find a ")" before the word "result" on line 56. It doesn't get plainer than that. You are missing a closing parenthesis.

yap as what you said and machine error.... i miss one " )" .. very appreciated... i am trying on the code now ....