indlæsning af speciel tekstfil?

Kode 

#include <stdio.h>

int main (int argc, char ** argv) {
    int row, id;
    float num;
    FILE * f;

    f = fopen("test.txt", "r");
    if (f) {
        while (!feof(f)) {
            fscanf(f, "%d\\t%d\\t%f\\n", &row, &id, &num);
            printf("Row: %d ID: %d Num: %f\\n", row, id, num);
        }
        fclose(f);
    } else {
        fprintf(stderr, "Could not open test.txt\\n");
        return 1;
    }

    return 0;
}

Kode 

robert-desktop:~ $ ./test 
Row: 1 ID: 1 Num: 1.000000
Row: 2 ID: 2 Num: 2287.030029
Row: 3 ID: 2 Num: 3843.830078
Row: 4 ID: 1 Num: 4.000000
Row: 5 ID: 2 Num: 3978.500000
Row: 6 ID: 2 Num: 3775.870117
Row: 7 ID: 1 Num: 702.000000
Row: 8 ID: 1 Num: 15.000000
Row: 9 ID: 2 Num: 0.000000
Row: 10 ID: 1 Num: 14.000000
Row: 11 ID: 2 Num: 19.480000
robert-desktop:~ $

Kode 

#include <iostream>
#include <string>
#include <sstream>
#include <fstream>
#include <list>

bool Split(const std::string str, int& nr, int& id, double& val)
{
   std::stringstream SS(str);
   return SS >> nr >> id >> val;
}

bool ValidSeq(std::list<int>& seq)
{
   if(seq.size() < 3)
      return false;
   std::list<int>::const_iterator it = seq.begin();
   switch(*it)
   {
   case 1:
      ++it;
      switch(*it)
      {
      case 1:
         ++it;
         switch(*it)
         {
         case 2:  // 1-1-2
            return true;
         case 3:  // 1-1-3
            return true;
         }
      case 2:
         switch(*it)
         {
         case 2:  // 1-2-2
            return true;
         case 3:  // 1-2-3
            return true;
         }
         break;
      }
      break;
   }
   return false;
}

int main()
{
   std::ifstream file("test.dat");
   std::string line;
   int nr, id;
   double val;
   std::list<int > seq;
   while(std::getline(file, line) && Split(line, nr, id, val))
   {
      seq.push_back(id);
      if(seq.size() > 3)
         seq.pop_front();
      if(ValidSeq(seq))
         std::cout << line << std::endl;
   }
}