剑指Offe [10] 矩形覆盖

package A10矩形覆盖;

public class Solution {

public int RectCover(int target) {

if (target <=0) {
return 0;
}
if (target == 1) {
return 1;
}

int a =1;
int b=0;
while(target-->0){
a = a+b;
b = a-b;
}
return b;
}
}