【c语言】用迭代计算斐波那契数

#include <stdio.h>
int fibonacci(int n)
{
	int result;
	int previous_result;
	int next_older_result;

	result = previous_result = 1;
	while(n > 2)
	{
	  n -= 1;
	  next_older_result = previous_result;
	  previous_result = result;
	  result = previous_result + next_older_result;
	}
	return result;
}
int main()
{
    int ret1 = fibonacci(1);
	int ret2 = fibonacci(6);
	printf("%d\n",ret1);
	printf("%d\n",ret2);
    return 0;
}