Задача на файли С++

[ozo]

#include <iostream>
#include <vector>
#include <fstream>
#include <iterator>
#include <algorithm>
#include <map>

bool IsAnagram( const std::string &left, const std::string &right ){
    if( left.size( ) != right.size( ) )
	return 0;
    for( int i = 0; i < left.size( ); ++i )
	if( std::count( left.begin( ), left.end( ), left[ i ] ) 
	    != std::count( right.begin( ), right.end( ), left[ i ] ) )
	    return 0;
    return 1;
}

bool IsHaveAnagram( const std::string &str, const std::vector< std::string > &vec ){
    for( int i = 0; i < vec.size( ); ++i )
	if( vec[ i ] != str && IsAnagram( str, vec[ i ] ) )
	    return 1;
    return 0;
}

int main(){
   std::ifstream in( "in.txt" );
   std::vector< std::string > source;
   if( in )
     source.assign( std::istream_iterator< std::string >( in ), std::istream_iterator< std::string >() );
   in.close();

   for( std::vector< std::string >::iterator i = source.begin( ); i != source.end( ); ++i )
       if( !IsHaveAnagram( *i, source ) ){
	   i = source.erase( i );
	   --i;
       }

   std::ofstream out( "out.txt" );
   std::copy( source.begin(), source.end(), std::ostream_iterator< std::string >( out, "\n" ) );
   out.close();
}

хи