Trapping Rain Water#11549
Given non-negative integers representing an elevation map where the width of each bar is .
Compute how much water it can trap after raining.
The first line contains the value of n~(n \le 10^5).
The second line contains non-negative integers h_1, h_2, ..., h_n~(h_i \le 10^5).
Print how much water can be trapped after raining.
Example 1
Example 2