递归和非递归分别实现求第n个斐波那契数

#define _CRT_SECURE_NO_WARNINGS 1
#include<stdio.h>
/////////////递归法实现
int Fac(int n)
{
if (n <= 2)
{
return 1;
}
else
{
return (Fac(n-1) + Fac(n - 2));
}
}
int main()
{
int a;
scanf("%d", &a);
int b = Fac(a);
printf("%d", b);
return 0;
}
///////////非递归法
#define _CRT_SECURE_NO_WARNINGS 1
#include<stdio.h>
int Fac(int n)
{
int Fac1 = 1;
int Fac2 = 1;
int Fac = 0;
int i = 3;
for (i = 3; i <= n; i++)
{
Fac = Fac1 + Fac2;
Fac1 = Fac2;
Fac2 = Fac;
}
return Fac;
}
int main()
{
int a;
scanf("%d", &a);
int b = Fac(a);
printf("%d", b);
return 0;
}