[C++知识库]C语言两种方法实现斐波那契数列

int Fb1(int i)
{
    int x1, x2, an, n;
    x1 = 0;
    x2 = 1;
    an = 1;
    n = 1;
    while (n < i)
    {
        n++;
        an = x1 + x2;
        x1 = x2;
        x2 = an;
    }
    return an;
}

首先是循环法。

int Fb2(int n)
{
    if((n == 1)||(n == 2))
    {
        return 1;
    }
    else
    {
        return (Fb2(n - 1) + Fb2(n - 2));
    }
}

然后是递归函数法。

#include <stdio.h>
#include <stdlib.h>
int Fb1(int i);
int Fb2(int n);
int main()
{
    int n;
    int x1, x2;
    scanf("%d", &n);

    x1 = Fb1(n);
    x2 = Fb2(n);
    printf ("%d\n%d", x1, x2);

    return 0;
}
int Fb1(int i)
{
    int x1, x2, an, n;
    x1 = 0;
    x2 = 1;
    an = 1;
    n = 1;
    while (n < i)
    {
        n++;
        an = x1 + x2;
        x1 = x2;
        x2 = an;
    }
    return an;
}
int Fb2(int n)
{
    if((n == 1)||(n == 2))
    {
        return 1;
    }
    else
    {
        return (Fb2(n - 1) + Fb2(n - 2));
    }
}

全部代码如上。