魔法兔子，秋n季节之后的总数

Question

。魔法兔子在果园生长，各个季节生长周期不同，秋n季节之后的总数。如图

Answer 1

代码如下：

#include <iostream>
using namespace std;
int main()
{
    int n, i;
    int a = 2, b = 4, c = 4;
    int t;
    cin >> n;
    if (n == 0)
        cout << 1;
    else if (n == 1 || n == 2)
        cout << 2;
    else if (n == 3 || n == 4)
        cout << 4;
    else
    {
        for (i = 5; i <= n; i++)
        {
            if (i % 2 == 0)
            {
                a = b;
                b = c;
                c = c; //
            }
            else
            {
                t = a + b + c;
                t = t % (1000000000 + 7);
                a = b;
                b = c;
                c = t;
            }
        }
        cout << c;
    }
    return 0;
}