斐波那契数列（递归与递推）

#include

using namespace std;

int Fib(int n)
{
	if(n <= 1) return n;
	
	return Fib(n - 1) + Fib(n - 2);
}
int main()
{
	int n;
	cout << "Give me an n: ";
	
	cin >> n;
	int result = Fib(n);
	cout << result;
	return 0;
}

 

#include

using namespace std;

int Fib(int n)
{
	if(n <= 1) return n;
	
	int F, F1 = 0, F2 = 1;
	for(int i = 2; i <= n; i++)
	{
		F = F1 + F2;
		F1 = F2;
		F2 = F;
	}
	
	return F;
}
int main()
{
	int n;
	cout << "Give me an n: ";
	
	cin >> n;
	int result = Fib(n);
	cout << result;
	return 0;
}