LeetCode: Climbing Stairs

You are climbing a stair case. It takes n steps to reach to the top.
Each time you can either climb 1 or 2 steps. In how many distinct ways can you climb to the top?

Solution:

public class Solution {
    public int climbStairs(int n) {
        int before2 = 0;
        int before1 = 1;
        for(int i=0; i<n; i++)
        {
            int temp = before2 +before1;
            before2 = before1;
            before1 = temp;
        }
        return before1;
    }
}