Sudoku Board Checker

board_checker.js

// sudoku board checker

function validateSet(row) {

  var hash = {};

  if(row.length === 9) {
    for(var idx = 0; idx < row.length; idx++) {
      hash[row[idx]] = row[idx];
    }

    for(var i in hash) {
      if(hash[i] <= 0 || hash[i] > 9) {
        return false;
      }
    }
  } else {
    return false;
  }

  return Object.keys(hash).length === 9 ? true : false;
}

function sudokuIsValid(board) {
  console.log('new board-----');

  var rows = {};
  var cols = {};
  var quads = {};

  // validate rows and columns
  for(var i = 0; i < board.length; i++) {
    rows[validateSet(board[i])] = validateSet(board[i]);
    var col = [];
    for(var j = 0; j < board[i].length; j++) {
      col.push(board[j][i]);
    }
    cols[validateSet(col)] = validateSet(col);

  }

  console.log('rows', rows);
  console.log('cols', cols);

  // validate quads
  var size = Math.sqrt(board.length),
    boxes = [];

  for(var r = 0, rl = board.length ; r < rl ; r++) {
    var row = board[r];
    for(var c = 0, cl = row.length ; c < cl ; c++) {
      var box = (r / size | 0) * size + (c / size | 0);
      boxes[box] || (boxes[box] = []);
      boxes[box].push(row[c]);
    }
  }

  for(var ii in boxes) {
    quads[validateSet(boxes[ii])] = validateSet(boxes[ii]);
  }

  console.log('quads', quads);

  if (rows.false || cols.false || quads.false) {
    return false;
  } else {
    return true;
  }
}

function test() {
  var VALID_SOLUTIONS = [
    [
      [9, 1, 6, 8, 4, 3, 5, 2, 7],
      [8, 4, 2, 7, 5, 6, 9, 3, 1],
      [7, 5, 3, 2, 9, 1, 8, 6, 4],
      [3, 6, 4, 9, 2, 7, 1, 8, 5],
      [2, 8, 1, 5, 6, 4, 7, 9, 3],
      [5, 9, 7, 1, 3, 8, 2, 4, 6],
      [6, 7, 8, 4, 1, 9, 3, 5, 2],
      [4, 2, 9, 3, 7, 5, 6, 1, 8],
      [1, 3, 5, 6, 8, 2, 4, 7, 9],
    ]
  ]

  var INVALID_SOLUTIONS = [
    [
      [9, 9, 6, 8, 4, 3, 5, 2, 7],
      [8, 4, 2, 7, 5, 6, 9, 3, 1],
      [7, 5, 3, 2, 9, 1, 8, 6, 4],
      [3, 6, 4, 9, 2, 7, 1, 8, 5],
      [2, 8, 1, 5, 6, 4, 7, 9, 3],
      [5, 9, 7, 1, 3, 8, 2, 4, 6],
      [6, 7, 8, 4, 1, 9, 3, 5, 2],
      [4, 2, 9, 3, 7, 5, 6, 1, 8],
      [1, 3, 5, 6, 8, 2, 4, 7, 9],
    ],
    [
      [9, 0, 6, 8, 4, 3, 5, 2, 7],
      [8, 4, 2, 7, 5, 6, 9, 3, 1],
      [7, 5, 3, 2, 9, 1, 8, 6, 4],
      [3, 6, 4, 9, 2, 7, 1, 8, 5],
      [2, 8, 1, 5, 6, 4, 7, 9, 3],
      [5, 9, 7, 1, 3, 8, 2, 4, 6],
      [6, 7, 8, 4, 1, 9, 3, 5, 2],
      [4, 2, 9, 3, 7, 5, 6, 1, 8],
      [1, 3, 5, 6, 8, 2, 4, 7, 9],
    ],
    [
      [9, 1, 6, 8, 4, 3, 5, 2, 7],
      [8, 4, 2, 7, 5, 6, 9, 3, 1],
      [7, 5, 9, 2, 9, 1, 8, 6, 4],
      [3, 6, 4, 9, 2, 7, 1, 8, 5],
      [2, 8, 1, 5, 6, 4, 7, 9, 3],
      [5, 9, 7, 1, 3, 8, 2, 4, 6],
      [6, 7, 8, 4, 1, 9, 3, 5, 2],
      [4, 2, 9, 3, 7, 5, 6, 1, 8],
      [1, 3, 5, 6, 8, 2, 4, 7, 9],
    ],
  ];

  for (var idx in VALID_SOLUTIONS) {
    var validSolution = VALID_SOLUTIONS[idx];
    if (!sudokuIsValid(validSolution)) {
      throw new Error('Valid solution failed');
    }

  }
  var invalidSolutions = [];
  for (var idx in INVALID_SOLUTIONS) {
    var invalidSolution = INVALID_SOLUTIONS[idx];
    if (sudokuIsValid(invalidSolution)) {
      invalidSolutions.push(new Error('Invalid solution failed'));
    }
  }
  console.log('invalidSolutions', invalidSolutions);
}


test();