Broken Bridge II

Create a function that returns the count of all bridges in a two-dimensional grid.

Bridge B should be counted if:

• It connects from one end of the grid to the one opposite to it.
• It is unobstructed.

Example

"#########/#       #/#   #   #/#   #   #/#### ####/#   #   #/#   #   #/#       #/#########"

In this case the number 4 is returned because, when unraveled, the string reveals four bridges that meet the requirements listed above as shown:

#########/
#       #/
#   #   #/
#   #   #/
#### ####/
#   #   #/
#   #   #/
#       #/
#########

Notes

• Slashes / act as separators.
• Intersecting bridges can still count, as shown.
• Vertical bridges count as long as the requirements are met.