Tic Tac Toe

Given a tic-tac-toe board, create a function that determines whether X won, O won, or there's a tie.

The board is represented as a 2-dimensional array. A board does not have to be completely filled. Blank squares are represented with the letter "B". For each board, X begins and O goes second.

Examples

whoWon([
  ["X", "O", "B"],
  ["B", "X", "O"],
  ["B", "B", "X"]
]) ➞ "X"

whoWon([
  ["X", "O", "X"],
  ["O", "X", "B"],
  ["X", "B", "O"]
]) ➞ "X"

whoWon([
  ["X", "X", "O"],
  ["O", "O", "X"],
  ["X", "X", "O"]
]) ➞ "Tie"

Notes

N/A