斐波那契数列迭代方法和递归算法对比

1.递归算法

int recursion(int n)        {            if (n < 2)                return n;            else            {                return recursion(n - 1) + recursion(n - 2);            }        }

2.递归算法（静态方法）

static int recursionS(int n)        {            if (n < 2)                return n;            else            {                return recursionS(n - 1) + recursionS(n - 2);            }        }

3.迭代算法

int Iteration(int n)        {            int a1, a2, a3;            if (n < 2)                return n;            a1 = a2 = a3 = 1;            while (n > 2)            {                n--;                a3 = a1 + a2;                a1 = a2;                a2 = a3;            }            return a3;        }

4.调用

Stopwatch sw1 = new Stopwatch();            sw1.Start();            int i = Iteration(40);            sw1.Stop();            Response.Write(string.Format("{1}迭代時間：{0}
", sw1.Elapsed, i));            Stopwatch sw = new Stopwatch();            sw.Start();            int r=  recursion(40);            sw.Stop();            Response.Write(string.Format("{1}遞歸時間：{0}", sw.Elapsed, r));            Response.Write("
");            Stopwatch sw2 = new Stopwatch();            sw2.Start();            int r1 = recursionS(40);            sw2.Stop();            Response.Write(string.Format("{1}遞歸時間(靜態)：{0}", sw2.Elapsed, r1));            Response.Write("
");

5.结果

102334155迭代時間：00:00:00.0001703

102334155遞歸時間：00:00:06.5017408

102334155遞歸時間(靜態)：00:00:06.2556308