斐波那契的递归和非递归算法实现

递归算法

int Fib(int n)

  {

      if(n==1 || n==2)

          return 1;

      else

          return Fib(n-1)+Fib(n-2);

 }

非递归算法

int Fib(int n)

  {

      if(n==1 || n==2)

          return 1;

      int fib1 = 1;

      int fib2 = 1;

      int fib;

      for(int i=3;i<=n;++i)

      {

           fib = fib1+fib2;

           fib2 = fib1;

           fib1 = fib;

      }

      return fib;

  }