Method findEmptyCell

Backtracking/Sudoku.js:7–15

()

  }

  findEmptyCell() {
    // Find a empty cell in the board (returns [-1, -1] if all cells are filled)
    for (let i = 0; i < 9; i++) {
      for (let j = 0; j < 9; j++) {
        if (this.board[i][j] === 0) return [i, j]
      }
    }
    return [-1, -1]
  }

  check([y, x], value) {
    // checks if the value to be added in the board is an acceptable value for the cell