Vfrdtyky

One of the text files is rainfallToDate.txt, and it has:

0.01

1.74

0.19

0.65

0.50

0.10

0.00

0.02

0.01

0.06

1.57

7.76

while the other is averageRainfall.txt:

2.99

3.32

2.04

1.06

0.39

0.09

0.00

0.00

0.23

0.78

1.88

2.12

I am supposed to merge these two text files into a text file called rainfall.txt

Here is a sample output:

Rainfall for Cupertino: A Comparison



Month    Average    2015    



1        2.99       0.01        

2        3.32       1.74      

3        2.04       0.19      

4        1.06       0.65       

5        0.39       0.50     

6        0.09       0.10      

7        0.00       0.00      

8        0.00       0.02      

9        0.23       0.01      

10       0.78       0.06      

11       1.88       1.57     

12       2.12       7.76     

As you can see averageRainfall.txt is stored on the row "average" while the other text file rainfallToDate.txt is stored under 2015.

Well here is what I have so far and my attempt on "merging" the two text files.

My attempt:

#include <iostream>  // for cout

#include <fstream>   // for file I/O

#include <cstdlib>   // for exit()



using namespace std;



int main()

{

ifstream fin;

ofstream fout;



if (fin.fail())

{

    cout << "Input file failed to open.n";

    exit(-1);

}

fout.open("rainfall.txt");

if (fout.fail())

{

    cout << "Output file failed to open.n";

    exit(-1);

}



fout << "Rainfall for Cupertino: A Comparisonn" << endl;

fout << "MonthtAveraget 2015tDeficitn" << endl;



   for (int i = 1; i <= 12; i++) { // counts the month from 1-12



    fout << fixed << i <<  endl;



}

fin.close();

fout.close();





// averageRainfall under averages

ifstream average;

ofstream oaverage;

average.open("averageRainfall.txt");

if (average.fail())

{

    cout << "Input file failed to open.n";

    exit(-1);

}

oaverage.open("rainfall.txt");

if (fout.fail())

{

    cout << "Output file failed to open.n";

    exit(-1);

}



oaverage << "t" << average;





// rainfallToDate under 2015

average.close();

oaverage.close();



ifstream ToDate;

ofstream oToDate;

ToDate.open("rainfallToDate.txt");

if (ToDate.fail())

{

    cout << "Input file failed to open.n";

    exit(-1);

}

oToDate.open("rainfall.txt");

if (oToDate.fail())

{

    cout << "Output file failed to open.n";

    exit(-1);

}



oToDate << "t" << "t" << ToDate;



ToDate.close();

oToDate.close();



return 0;

}

Now for the problem, the code runs and all doesn't state any kind of error, however, when I open up the file where both the code merges the file prints out

0x29fe64

What I believe I did wrong is that I didn't put the two textfiles "averages" and the "rainfalltodate" into two separate arrays and stating it from there. Correct me if I am wrong not very sure if I am supposed two put both of them in two separate arrays.

oToDate << "t" << "t" << ToDate;

I guess your intention here is to copy everything from the ToDate stream to the oToDate stream, but that's not quite what's happening. Instead, this is just attempting to write out a single value which represents ToDate -- which turns out to be the (meaningless) pointer address of the variable.

However, even if we fix this we can't quite do what you want at the moment. It looks like you're trying to first copy the average rainfall data, then in the second pass, skip what you've just written and put the rainfall to date next to it. But this isn't going to work -- the second pass is just going to overwrite the existing line.

Instead, what you need to do is to load up both datasets, and write them out in one go. One option is to load the two datasets separately and use a std::vector to hold the values before you write them back out. Let's see how we can do this:

std::ifstream average{"averageRainfall.txt"};

std::vector<double> average_data;



std::copy(std::istream_iterator<double>{average},

          std::istream_iterator<double>{},

          std::back_inserter(average_data));

This will copy all the data from the input file into a vector (make sure you look up these functions if you haven't seen them before so you know what's going on here!). We can do exactly the same for the second data set, so let's say we save that into a vector called to_date_data.

We then need to write both values out to a file at the same time. First, we open the output file:

std::ofstream rainfall{"rainfall.txt"};

Then we loop through the two vectors, copying the data to the output stream:

auto last = std::min(average_data.size(), to_date_data.size());



for (int i = 0; i < last; i++) {

    rainfall << average_data[i] << "t" << to_date_data[i] << "n";

}

and you're all done :-)

Your strange output comes from this line:

oaverage << "t" << average;

average is a stream, and not a numerical value. When you try to print the stream, the stream ends up being converted to a pointer, and you are seeing a pointer value instead.

There's a similar issue on this line:

oToDate << "t" << "t" << ToDate;

maybe you should read some basic C++ programming book,here is my code:

#include <iostream>  // for cout

#include <fstream>   // for file I/O

#include <cstdlib>   // for exit()

using namespace std;

int main()

{

  std::ifstream fin_rain_date("rainfallToDate.txt");

  std::ifstream fin_rain_ave("averageRainfall.txt");

  if(fin_rain_ave==NULL||fin_rain_date==NULL)

  {

    std::cout<<"can not open file"<<std::endl;

  }

  std::ofstream fout("rainfall.txt");

  fout<<"Rainfall for Cupertino: A Comparison"<<std::endl;

  fout<<"MonthtAveraget 2015tDeficit"<<std::endl;

  for(int i=0;i<12;i++)

  {

    fout<<i<<"t";

    char tmpstr[256];

    fin_rain_ave.getline(tmpstr,256);

    fout<<tmpstr<<"t";

    fin_rain_date.getline(tmpstr,256);

    fout<<tmpstr<<std::endl;

  }

  return 0;

}