Tic Tac Toe 1.0

/*
 * Program : Tic Tac Toe
 * Author  : Michael Stroud
 * Version : 1.0
 * Date    : 20141002
 * Purpose : A simple 2 player tic tac toe game for the command line.
*/
#include <iostream>
#include <limits>

char gameboard[3][3] = {{'7','8','9'},
    {'4','5','6'},
    {'1','2','3'}};
char playerSymbols[] = {'X','O'};
void drawboard();
void processPlayerMove(int);
int getCoord();
int xFromCoord(int coord);
int yFromCoord(int coord);

enum gamestate{
    UNFINISHED,
    XWINS,
    OWINS,
    DRAW
};
gamestate getGameState(int);
int main(){
    std::cout << "***TIC TAC TOE***" << std::endl;
    drawboard();
    int elapsedTurns = 0;
    while (getGameState(elapsedTurns) == UNFINISHED){
        processPlayerMove(elapsedTurns%2);
        drawboard();
        ++elapsedTurns;
    }
    switch (getGameState(elapsedTurns)){
        case DRAW:
            std::cout << "Cat's game." << std::endl;
            break;
        case XWINS:
            std::cout << "Player 1 wins." << std::endl;
            break;
        case OWINS:
            std::cout << "Player 2 wins." << std::endl;
            break;

    }
}

void drawboard(){
    for (int i = 0; i < 3; ++i){
        for (int k = 0; k < 3; ++k){
            std::cout << " " << gameboard[i][k];
            if (k < 2){
                std::cout << " |";
            }
        }
        std::cout << std::endl;
        if (i < 2){
            std::cout << "---+---+---" << std::endl;
        }
    }
}

void processPlayerMove(int playerNumber){
    std::cout << "Player " << playerNumber+1 << " choose where to place \'" <<
        playerSymbols[playerNumber] << "\'" << std::endl;
    int targetCoord = getCoord();
    while (gameboard[yFromCoord(targetCoord)][xFromCoord(targetCoord)] != (targetCoord+'0')){
        std::cout << "That spot is occupied. Please choose another spot." << std::endl;
        targetCoord = getCoord();
    }
    gameboard[yFromCoord(targetCoord)][xFromCoord(targetCoord)] =playerSymbols[playerNumber];
}

int getCoord(){
    char userIn;
    do {
        std::cin >> userIn;
    }while (userIn < '0' || userIn > '9');
    std::cin.clear();
    std::cin.ignore(std::numeric_limits<std::streamsize>::max(),'\n');
    return userIn-'0';
}

int yFromCoord(int coord){
    int zeroedCoord = coord-1;
    zeroedCoord = 8-zeroedCoord;
    return zeroedCoord/3;
}

int xFromCoord(int coord){
    int zeroedCoord = coord-1;
    return zeroedCoord%3;
}

gamestate getGameState(int elapsedTurns){
    if (elapsedTurns < 5){
        return UNFINISHED;
    }
    //check for vertical win
    for (int i = 0; i < 3; i++){
        if (gameboard[0][i] == gameboard[1][i] &&
                gameboard[0][i] == gameboard[2][i]){
            if (gameboard[0][i] == 'X'){
                return XWINS;
            }else{
                return OWINS;
            }
        }
    }
    //check for horizontal win
    for (int i = 0; i < 3; i++){
        if (gameboard[i][0] == gameboard[i][1] &&
                gameboard[i][0] == gameboard[1][2]){
            if (gameboard[i][0] == 'X'){
                return XWINS;
            }else{
                return OWINS;
            }
        }
    }
    //check for diagonal win
    if (gameboard[0][0] == gameboard[1][1] &&
            gameboard[0][0] == gameboard[2][2]){
        if (gameboard[0][0] == 'X'){
            return XWINS;
        }else{
            return OWINS;
        }
    }
    if (gameboard[2][0] == gameboard [1][1] &&
            gameboard[2][0] == gameboard[0][2]){
        if (gameboard[2][0] == 'X'){
            return XWINS;
        }else{
            return OWINS;
        }
    }
    if (elapsedTurns == 9){
        return DRAW;
    }
    return UNFINISHED;
}