Climbing Stairs - 2

class Solution {
    public int climbStairs(int n) {
        if(n==0 || n==1 || n==2) {
            return n;
        }

        int[] cache = new int[n+1];

        for(int i=0; i<=2; i++) {
            cache[i] = i;
        }
        for(int i=3; i<=n; i++) {
            cache[i] = cache[i-1] + cache[i-2];
        }
        return cache[n];
    }
}