Task: Text processing_2
C#: using System;
using System.Collections.Generic;
using System.Text.RegularExpressions;
using System.IO;

namespace TextProc2
{
    class Program
    {
        static void Main(string[] args)
        {
            Regex multiWhite = new Regex(@"\s+");
            Regex dateEx = new Regex(@"^\d{4}-\d{2}-\d{2}$");
            Regex valEx = new Regex(@"^\d+\.{1}\d{3}$");
            Regex flagEx = new Regex(@"^[1-9]{1}$");
            
            int missformcount = 0, totalcount = 0;
            Dictionary<int, string> dates = new Dictionary<int, string>();

            using (StreamReader sr = new StreamReader("readings.txt"))
            {
                string line = sr.ReadLine();
                while (line != null)
                {
                    line = multiWhite.Replace(line, @" ");                    
                    string[] splitLine = line.Split(' ');
                    if (splitLine.Length != 49)
                        missformcount++;
                    if (!dateEx.IsMatch(splitLine[0]))                        
                        missformcount++;                    
                    else
                        dates.Add(totalcount + 1, dateEx.Match(splitLine[0]).ToString());
                    int err = 0;                    
                    for (int i = 1; i < splitLine.Length; i++)
                    {
                        if (i%2 != 0)
                        {
                            if (!valEx.IsMatch(splitLine[i]))                          
                                err++;
                        }
                        else
                        {
                            if (!flagEx.IsMatch(splitLine[i]))
                                err++;                                                        
                        }                        
                    }
                    if (err != 0) missformcount++;
                    line = sr.ReadLine();
                    totalcount++;                    
                }
            }

            int goodEntries = totalcount - missformcount;
            Dictionary<string,List<int>> dateReverse = new Dictionary<string,List<int>>();

            foreach (KeyValuePair<int, string> kvp in dates)
            {
                if (!dateReverse.ContainsKey(kvp.Value))
                    dateReverse[kvp.Value] = new List<int>();
                dateReverse[kvp.Value].Add(kvp.Key);
            }

            Console.WriteLine(goodEntries + " valid Records out of " + totalcount);

            foreach (KeyValuePair<string, List<int>> kvp in dateReverse)
            {
                if (kvp.Value.Count > 1)
                    Console.WriteLine("{0} is duplicated at Lines : {1}", kvp.Key, string.Join(",", kvp.Value));                    
            }
        }
    }
}

C++: #include <boost/regex.hpp>
#include <fstream>
#include <iostream>
#include <vector>
#include <string>
#include <set>
#include <cstdlib>
#include <algorithm>
using namespace std ;

boost::regex e ( "\\s+" ) ; 

int main( int argc , char *argv[ ] ) { 
   ifstream infile( argv[ 1 ] ) ; 
   vector<string> duplicates ;
   set<string> datestamps ; 
   if ( ! infile.is_open( ) ) { 
      cerr << "Can't open file " << argv[ 1 ] << '\n' ;
      return 1 ; 
   }   
   int all_ok = 0  ;
   int pattern_ok = 0 ; 
   while ( infile ) { 
      string eingabe ;
      getline( infile , eingabe ) ;
      boost::sregex_token_iterator i ( eingabe.begin( ), eingabe.end( ) , e , -1 ), j  ;
      vector<string> fields( i, j ) ;
      if ( fields.size( ) == 49 ) 
         pattern_ok++ ;
      else
         cout << "Format not ok!\n" ;
      if ( datestamps.insert( fields[ 0 ] ).second ) { 
         int howoften = ( fields.size( ) - 1 ) / 2 ;
                                                    
         for ( int n = 1 ; atoi( fields[ 2 * n ].c_str( ) ) >= 1 ; n++ ) {
            if ( n == howoften ) {
               all_ok++ ;
               break ;
            }
         }
      }
      else {
         duplicates.push_back( fields[ 0 ] ) ;
      }
   }
   infile.close( ) ;
   cout << "The following " << duplicates.size() << " datestamps were duplicated:\n" ;
   copy( duplicates.begin( ) , duplicates.end( ) ,
         ostream_iterator<string>( cout , "\n" ) ) ;
   cout << all_ok << " records were complete and ok!\n" ;
   return 0 ;
}