​

function shuffle(o){

      for (var j, x, i = o.length; i; j = Math.floor(Math.random() * i), x = o[--i], o[i] = o[j], o[j] = x);

      return o;

  };

​

var width = 10

  , height = 10

​

// initialize the grid

    var grid = []

      , cells = []

      // duplicate to avoid overriding

      , w = width

      , h = height

    while (w--) cells.push(0)

    while (h--) grid.push(cells)

​

    var N = 1

      , S = 2

      , E = 4

      , W = 8

      , dirs = ['N', 'E', 'S', 'W']

      , dirsValue = { N: N, E: E, S: S, W: W }

      , DX = { E: 1, W: -1, N: 0, S: 0 }

      , DY = { E: 0, W: 0, N: -1, S: 1 }

      , OPPOSITE = { E: W, W: E, N: S, S: N }

​

    function carve_passages_from(cx, cy, grid) {

      var directions = shuffle(dirs)

​

      directions.forEach(function(direction) {

        var nx = cx + DX[direction]

          , ny = cy + DY[direction]

​

        if (ny >= 0 && ny <= (grid.length - 1) && nx >= 0

          && nx <= (grid.length - 1) && grid[ny][nx] === 0) {

          grid[cy][cx] += dirsValue[direction]

          grid[ny][nx] += OPPOSITE[direction]

          carve_passages_from(nx, ny, grid)

        }

      })

    }

​

    carve_passages_from(0, 0, grid)

​

    document.querySelector('div').innerHTML = grid