【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;}