#include <iostream>
#include <fstream>
#include <string>

using namespace std;

void main()
{
	cout << "Formatting...\n\n";

	fstream fin("input.txt");
	fstream fout("output.txt", ios::out);

	if (fin && fout)
	{
		char nextLine[50000];
		string fileContents = "";

		fin.getline(nextLine, 50000);

		//Read the entire file into the fileContents string.
		while (fin)
		{
			fileContents += nextLine;

			fin.getline(nextLine, 50000);

			if (fin)
			{
				fileContents += "\n";
			}
		}
		
		int fileLength = strlen(fileContents.c_str());

		string fileOutputContents = "";

		int digitNum = 0;

		for (int i = 0; i < fileLength; ++i)
		{
			//Completely skip the dashes.
			if (fileContents[i] != '-')
			{
				//If it's a new column, reset the digit count and output the new line or comma character like normal.
				if (fileContents[i] == '\n' || fileContents[i] == ',')
				{
					digitNum = 0;
					fileOutputContents += fileContents[i];
				}
				else
				{
					//We're assuming it's a digit now.

					//Check to make sure that this either isn't the first digit in the number or that it's not a 1.
					if (digitNum > 0 || fileContents[i] != '1')
					{
						//If so, output the character.
						fileOutputContents += fileContents[i];

						//Check to see if it's the third digit in the number; if so, output a comma.
						if (digitNum == 2)
						{
							fileOutputContents += ',';
						}

						//Increase the digit counter.
						++digitNum;
					}
				}
			}
		}

		fout << fileOutputContents;

		cout << "Phone numbers formatted successfully! Check \"output.txt\".";
	}
	else
	{
		cout << "Error either opening \"input.txt\" for reading or opening \"output.txt\" for writing.";
	}

	fout.close();
	fin.close();

	cout << "\n\n";

	system("pause");
}