剑指Offer的学习笔记（C#篇）-- 矩形覆盖

class Solution {
    public int rectCover(int number)
       {
            if(number <= 0)
            {
                return 0;
            }

            if(number == 1)
            {
                return 1;
            }

            if(number == 2)
            {
                return 2;
            }

            return rectCover(number - 1) + rectCover(number -2 );

class Solution
{
    public int rectCover(int number)
    {
        // write code here
        int sum = 0;
        int a=1,b=2;
        if (number == 1)
        {
            sum = 1;
        }
        else if (number==2)
        {
            sum = 2;
        }
         else
         {
            for (int i = 3; i <=number; i++)
               {
                 sum = a + b;
                 a = b;
                 b = sum;
               }
         }
         return sum;
    }
}

number