Finding contiguous blocks in a 2D array
Say you had an array in the form:

    [ 
      [2, 2, 3, 4],
      [2, 3, 5, 5],
      [2, 2, 2, 5],
      [3, 2, 2, 4],
    ]

and wanted to find coordinates of numerically contiguous blocks, in this case:

    [
      # the 2s:
      [(0,0), (0,1), (1,0), (2,0), (2,1), (2,2), (3,1), (3,2)],
      # and the 5s:
      [(1,2), (1,3), (2,3)]
    ]

how would you do it?

Finding contiguous blocks in a 2D array
===

Say you had an array in the form:

    [ 
      [2, 2, 3, 4],
      [2, 3, 5, 5],
      [2, 2, 2, 5],
      [3, 2, 2, 4],
    ]

and wanted to find coordinates of numerically contiguous blocks, in this case:

    [
      # the 2s:
      [(0,0), (0,1), (1,0), (2,0), (2,1), (2,2), (3,1), (3,2)],
      # and the 5s:
      [(1,2), (1,3), (2,3)]
    ]

how would you do it?
