Given a triangle, find the minimum path sum from top to bottom. Each step you
may move to adjacent numbers on the row below.
For example, given the following triangle
[ [ **2** ], [ **3** ,4], [6, **5** ,7], [4, **1** ,8,3] ]
The minimum path sum from top to bottom is
11 (i.e., 2 + 3 + 5
+ 1 = 11).
Bonus point if you are able to do this using only O ( n ) extra space,
where n is the total number of rows in the triangle.
Tags: Array, Dynamic Programming