Given a “2 x n” board and tiles of size “2 x 1”, count the number of ways to tile the given board using the 2 x 1 tiles. A tile can either be placed horizontally i.e., as a 1 x 2 tile or vertically i.e., as 2 x 1 tile.
Examples:
Input: n = 4
Output: 5
Explanation:
For a 2 x 4 board, there are 5 ways
All 4 vertical (1 way)
All 4 horizontal (1 way)
2 vertical and 2 horizontal (3 ways)
Tiling Problem (Explanation) : https://www.geeksforgeeks.org/tiling-problem/