TicTacToe

#include <iostream>
#include <vector>
#include <unistd.h>
using namespace std;
bool Complete = false;
bool PlayerTurn = true;
bool LegalMove = false;
bool IsStillPossibleToWin = false;
string PlayerCheck;
string Answer;
string PlayerOne = "X";
string PlayerTwo = "O";
string PlayerThree = "Y";
int PlayerWhoWon;

vector<string> TicTacToe {"1", "2", "3", "4", "5", "6", "7", "8", "9"};

bool PlayAgain() {
    cout << "Want to play again?\n";
    cin >> Answer;
    if (Answer == "yes" || Answer == "Yes" || Answer == "Y" || Answer == "y") {
        return true;
    } else if (Answer == "No" || Answer == "no" || Answer == "N" || Answer == "n") {
        return false;
    } else {
        PlayAgain();
    }
}

void Track() {
    for (int Repeats = 30; Repeats >= 0; Repeats--) {
        cout << "\n";
    }
    cout << " " << TicTacToe[0] << " | " << TicTacToe[1] << " | " << TicTacToe[2] << "\n";
    cout << "----------\n";
    sleep(0.25);
    cout << " " << TicTacToe[3] << " | " << TicTacToe[4] << " | " << TicTacToe[5] << "\n";
    sleep(0.25);
    cout << "----------\n";
    sleep(0.25);
    cout << " " << TicTacToe[6] << " | " << TicTacToe[7] << " | " << TicTacToe[8] << "\n";
    sleep(0.25);
    cout << "\n\n";
}

void Turn() {
    do {
        if (PlayerTurn) {
            cout << "X ";
        } else {
            cout << "O ";
        }
        cin >> Answer;
        if (Answer == "1" && TicTacToe[0] == "1") {
            LegalMove = true;
            TicTacToe[0] = PlayerCheck;
        } else if (Answer == "2" && TicTacToe[1] == "2") {
            LegalMove = true;
            TicTacToe[1] = PlayerCheck;
        } else if (Answer == "3" && TicTacToe[2] == "3") {
            LegalMove = true;
            TicTacToe[2] = PlayerCheck;
        } else if (Answer == "4" && TicTacToe[3] == "4") {
            LegalMove = true;
            TicTacToe[3] = PlayerCheck;
        } else if (Answer == "5" && TicTacToe[4] == "5") {
            LegalMove = true;
            TicTacToe[4] = PlayerCheck;
        } else if (Answer == "6" && TicTacToe[5] == "6") {
            LegalMove = true;
            TicTacToe[5] = PlayerCheck;
        } else if (Answer == "7" && TicTacToe[6] == "7") {
            LegalMove = true;
            TicTacToe[6] = PlayerCheck;
        } else if (Answer == "8" && TicTacToe[7] == "8") {
            LegalMove = true;
            TicTacToe[7] = PlayerCheck;
        } else if (Answer == "9" && TicTacToe[8] == "9") {
            LegalMove = true;
            TicTacToe[8] = PlayerCheck;
        }
    } while (LegalMove != true);
    LegalMove = false;
    if (TicTacToe[0] == TicTacToe[4] && TicTacToe[4] == TicTacToe[8] || TicTacToe[0] == TicTacToe[3] && TicTacToe[3] == TicTacToe[6]) {
        Complete = true;
        if (PlayerTurn) {
            PlayerWhoWon = 1;
        } else {
            PlayerWhoWon = 2;
        }
    } else if (TicTacToe[0] == TicTacToe[1] && TicTacToe[1] == TicTacToe[2] || TicTacToe[1] == TicTacToe[4] && TicTacToe[4] == TicTacToe[7]) {
        Complete = true;
        if (PlayerTurn) {
            PlayerWhoWon = 1;
        } else {
            PlayerWhoWon = 2;
        }
    } else if (TicTacToe[2] == TicTacToe[4] && TicTacToe[4] == TicTacToe[6] || TicTacToe[3] == TicTacToe[4] && TicTacToe[4] == TicTacToe[5]) {
        Complete = true;
        if (PlayerTurn) {
            PlayerWhoWon = 1;
        } else {
            PlayerWhoWon = 2;
        }
    } else if (TicTacToe[2] == TicTacToe[5] && TicTacToe[5] == TicTacToe[8] || TicTacToe[6] == TicTacToe[7] && TicTacToe[7] == TicTacToe[8]) {
        Complete = true;
        if (PlayerTurn) {
            PlayerWhoWon = 1;
        } else {
            PlayerWhoWon = 2;
        }
    } else {
        if (TicTacToe[0] == "1" || TicTacToe[1] == "2" || TicTacToe[2] == "3" || TicTacToe[3] == "4" ||TicTacToe[4] == "5" || TicTacToe[5] == "6" ||
            TicTacToe[6] == "7" || TicTacToe[7] == "8" || TicTacToe[8] == "9") {
            IsStillPossibleToWin = true;
        } else {
            IsStillPossibleToWin = false;
        }
        if (IsStillPossibleToWin == false) {
            Complete = true;
            PlayerWhoWon = 3;
        }
    }
    if (PlayerTurn) {
        PlayerTurn = false;
    } else {
        PlayerTurn = true;
    }
}

int main() {
    Track();
    do {
        if (PlayerTurn) {
            cout << "Its player ones turn.\n";
            PlayerCheck = PlayerOne;
        } else {
            cout << "Its player twos turn.\n";
            PlayerCheck = PlayerTwo;
        }
        Turn();
        Track();
    } while (Complete != true);
    if (PlayerWhoWon == 1) {
        cout << "Player one won!\n";
    } else if (PlayerWhoWon == 2) {
        cout << "Player two won!\n";
    } else {
        cout << "It was a tie!\n";
    }
    if (PlayAgain() == true) {
        TicTacToe[0] = "1";
        TicTacToe[1] = "2";
        TicTacToe[2] = "3";
        TicTacToe[3] = "4";
        TicTacToe[4] = "5";
        TicTacToe[5] = "6";
        TicTacToe[6] = "7";
        TicTacToe[7] = "8";
        TicTacToe[8] = "9";
        Complete = false;
        PlayerTurn = true;
        main();
    }
}