fibonacci算法

int hi,lo;

hi=lo=1;

hi=hi+lo; //2 3 5 8 13 ……

lo=hi-lo;

 

unsigned int Fib1(unsigned int n)

{

    if (n == 1 || n == 2)        

           return 1;    

   else        

           return Fib(n - 1) + Fib(n - 2);

}
unsigned int Fib2(unsigned int n)

{    

    unsigned int nRet, nP, nPp;
    nRet = nP = nPp = 1;

    if ((n == 1) || (n == 2))
        return nRet;

    for (unsigned int i = 3; i <= n; i++)
    {
        nRet = nP + nPp;

        nPp = nP;
        nP = nRet;
    }

    return nRet;
}