剑指offer之矩形覆盖

public class Solution {    public int RectCover(int target) {        //int dp[] = new int[target + 5];        if(target==0) return 0;        if(target==1) return 1;        int k0 = 0;        int k1 = 1;        int res = k1 + k0;        for(int i = 2; i <= target; ++i) {            k0 = k1;            k1 = res;            res = k0 + k1;        }        return res;    }}