10、矩形覆盖

我们可以用2*1的小矩形横着或者竖着去覆盖更大的矩形。请问用n个2*1的小矩形无重叠地覆盖一个2*n的大矩形，总共有多少种方法？

===============Python=============

# -*- coding:utf-8 -*-
class Solution:
    def rectCover(self, number):
        # write code here
        if number == 0:
            return 0
        dp1 = 1
        dp2 = 2
        for i in range(1, number):
            dp1, dp2 = dp2, dp1 + dp2
        return dp1

===============Java==============

public class Solution {
    public int RectCover(int target) {
        if (target == 0) return 0;
        int dp1 = 1;
        int dp2 = 2;
        for (int i = 1; i < target; i++) {
            int tmp = dp1;
            dp1 = dp2;
            dp2 += tmp;
        }
        return dp1;
    }
}