Tie-tac-toe homework

gistfile1.js

/**
 * Check if the given slot is empty (no piece placed)
 */
function isEmpty(s) {
  return s !== 'x' && s !== 'o';
}

/**
 * Get the state for a row with three slots
 */
function getRowState(s1, s2, s3) {
  if(s1 === 'x' && s2 === 'x' && s3 === 'x') {
    // All three slots are 'x'. The winner is x
    return 'x';
  }
  
  (PLEASE FINISH THE FUNCTION HERE)
}

// Let's test the function with different cases
console.log(getRowState('x', 'x', 'x'));

(PLEASE ADD MORE TESTS)

/**
 * Get the state of tic-tac-toe board
 * @param board An array with 9 slots. Each slot can have
 * a value of 'x', 'o', or ' '.
 */
function getBoardState(board) {
  var rows = [];
  rows[0] = getRowState(board[0], board[1], board[2]);
  rows[1] = getRowState(board[3], board[4], board[5]);
  rows[2] = getRowState(board[6], board[7], board[8]);
  rows[3] = getRowState(board[0], board[3], board[6]);
  rows[4] = getRowState(board[1], board[4], board[7]);
  rows[5] = getRowState(board[2], board[5], board[8]);
  rows[6] = getRowState(board[0], board[4], board[8]);
  rows[7] = getRowState(board[2], board[4], board[6]);
  
  // Use a flag to track if the game is still in progress
  var inProgress = false;
  for(var i=0; i<rows.length; i++) {
    if(rows[i] === 'x') {
      // Found a row with 3 'x': x wins
      return 'x';
    }
    if(rows[i] === 'o') {
      // Found a row with 3 'o': o wins
      return 'o';
    }
    if(rows[i] === 'i') {
      // The game is in progress so far
      inProgress = true;
    }
  }
  
  if(inProgress) {
    // One of the rows still has empty slots
    return 'i';
  }
  
  // All slots are taken, it's a tie
  return 't';
 
}

// Let's run some tests
var board = ['x', 'o', ' ', ' ', ' ', 'x', 'o', 'x', 'o'];
console.log('Result: ' + getBoardState(board));

board = ['x', 'o', 'x', 'x', 'x', 'o', 'o', 'x', 'o'];
console.log('Result: ' + getBoardState(board));

board = ['x', 'o', 'o', 'x', 'x', 'x', 'o', 'x', 'o'];
console.log('Result: ' + getBoardState(board));

board = ['o', 'o', 'o', 'x', ' ', 'x', 'x', 'x', 'o'];
console.log('Result: ' + getBoardState(board));