Total number of ways to climb the staircase is given recursively as:
T(n) = T(n-1) + T(n-2) for n >= 3.
T(1) = 1
T(2) = 2
The minimum number of steps to climb is n/2 if n is even else [n/2] + 1 where [x] denotes greatest integer less than or equal to x.