Write a method named water that accepts an array of vertical bar heights as its parameter and returns the largest rectangular area of water that could be held in a contiguous region between those bars. For example, if the bar heights are {2, 9, 6, 2, 4, 5, 8, 3, 7, 4}, the bars could be thought of as follows:

  #
  #         #
  #         #   #
  # #       #   #
  # #     # #   #
  # #   # # #   # #
  # #   # # # # # #
# # # # # # # # # #
# # # # # # # # # #
2 9 6 2 4 5 8 3 7 4

The largest area of water that can be made within these bars has an area of 49 (7*7 for height*(idx 8 - idx 1)-assuming the region between was empty).

If the array contains fewer than 2 bars, return 0.