You are given an array with element represents the height of a tower with width equal to one unit. It started to rain. Find the amount of water trapped between towers?
For example, tower = [0, 1, 2, 1, 3, 2, 0, 2, 3] – then answer is 6 units between towers 3 and 7.
Given n non-negative integers representing the height of bars of width one of a histogram, find the maximum area rectangle of histogram i.e. the maximum area rectangle contained in the histogram.
For example, H = [4, 2, 1, 8, 6, 8, 5, 2] then the histogram has a rectangle of area of 20 showed in shaded.