斐波那契数列
斐波那契数列指的是这样一个数列 1, 1, 2, 3, 5, 8, 13, 21, 34, 55, 89, 144, 233,377,610,987,1597,2584,4181,6765,10946,17711,28657,46368........
自然中的斐波那契数列
这个数列从第3项开始,每一项都等于前两项之和。
/// <summary>
/// 循环
/// </summary>
/// <param name="n"></param>
/// <returns></returns>
public static int GetFbin(int n)
{
if (n < 2)
return 1;
int n1 = 1;
int n2 = 1;
int fib = 0;
for (int i = 2; i <= n; i++)
{
fib = n1 + n2;
n2 = n1;
n1 = fib;
}
return fib;
}
/// <summary>
/// 递归
/// </summary>
/// <param name="n"></param>
/// <returns></returns>
public static int GetFbin2(int n)
{
if (n < 2)
return 1;
return GetFbin2(n -2) + GetFbin2(n -1);
}