[Leetcode] climbing stairs

Question: given an integer n of the int type, it indicates the order of the stairs. You can take one or two steps each time you take the stairs to find out how many different methods are there to walk the stairs of the N level.

Algorithm: recursion is the simplest method, but Will time out; recursive conversion to recursive formula: F (n) = f (n-1) + f (n-2)

Public class solution {public int climbstairs (int n) {final int stairs = 50; int [] nsteps = new int [Stairs]; nsteps [0] = 0; nsteps [1] = 1; nsteps [2] = 2; nsteps [3] = 3; for (INT I = 4; I <stairs; ++ I) {nsteps [I] = nsteps [I-1] + nsteps [I-2];} return nsteps [N];}