Multithreaded Primes

// MultithreadingPrimeNumbers.cpp : Defines the entry point for the console application.
//Authored by Jared White
#include "stdafx.h"
#include <iostream>
#include <vector>
#include <fstream>
#include <string>
#include <thread>
using namespace std;

//Config
const unsigned char NumberOfThreads = 8;

//Vars
unsigned long long int CurrentNumber[NumberOfThreads];      //CurrentNumber, 1 per thread
string MessageQueue[NumberOfThreads];                       //Messages to be written, 1 per thread
vector<unsigned long long int> PrimeNumbers;                //Stores primes to be written to file
const string OutputFileName = "Primes.txt";                 //Filename to write primes to

//Prototypes
void CheckForPrime(unsigned long long int Number, const unsigned char ThreadNumber);
void WriteNumber(unsigned long long int Number);
void QueueMessage(unsigned long long int Number, unsigned char Thread, bool IsPrime);
void WritePrimes(void);
void Log(void);

//Main program
void CheckForPrime(unsigned long long int Number, const unsigned char ThreadNumber) {
    unsigned int LastDigit = Number % 10;
    if (LastDigit == 0 || (LastDigit % 2 == 0)) {           //Check if even
        QueueMessage(Number, ThreadNumber, false);
        CurrentNumber[ThreadNumber] += NumberOfThreads;
        return;
    }

    for (unsigned long long int i = 2; i < Number; i++) {
        if (Number % i == 0) {                              //Not prime, divisible by more than 1 and itself
            QueueMessage(Number, ThreadNumber, false);
            CurrentNumber[ThreadNumber] += NumberOfThreads;
            return;
        }
    }
    //If reached, is prime
    //cout << "\n\n\n\n test \n" << Number << "\n\n\n\n";
    PrimeNumbers.push_back(Number);                         //Add number to vector of nums to be written to file
    QueueMessage(Number, ThreadNumber, true);
    CurrentNumber[ThreadNumber]+=NumberOfThreads;
    return;

}

void WriteNumber(unsigned long long int Number) {
    ofstream OutputFile;
    OutputFile.open(OutputFileName, ios::app);
    OutputFile << Number << endl;
    OutputFile.close();
    return;
}

void QueueMessage(unsigned long long int Number, unsigned char Thread, bool IsPrime) {
    string EndMessage = "Not Prime\n";
    if (IsPrime) { EndMessage = "Is Prime\n"; }
    MessageQueue[Thread] = "[T:" + to_string(Thread) + "][N:" + to_string(Number) + "] " +  EndMessage; //Create message
    return;
}

void WritePrimes(void) {
    for each (unsigned long long int Number in PrimeNumbers)
    {
        WriteNumber(Number);
    }

    PrimeNumbers.clear();

    return;
}

void Log(void) {
    for each (string str in MessageQueue)
    {
        cout << str;
    }
}

int main()
{
    //remove(OutputFileName.c_str());                                   //Delete file if it already exsists
    thread PrimeThreads[NumberOfThreads];                           //Create threads
    bool Run = true;
    for (int i = 0; i < NumberOfThreads; i++) {
        CurrentNumber[i] = i + 2;                                   //The +2 prevents false positives in the CheckPrime code
    }

    while (Run) {

        for (unsigned char i = 0; i < NumberOfThreads; i++)         //Set up threads
        {
            PrimeThreads[i] = thread(CheckForPrime, CurrentNumber[i], i);
        }

        for (unsigned char i = 0; i < NumberOfThreads; i++) {
            PrimeThreads[i].join();
        }

        WritePrimes();                                              //Write primes to file
        Log();                                                      //Log the results of the threads to the console

    }



    cin.ignore();
    return 0;

}