# coding: utf-8 class Solution: # @param n: an integer # @return an integer f(n) def fibonacci(self, n): # write your code here if (n == 1) or (n == 2): return n - 1 ret = 0 f_1, f_2 = 0, 1 for i in range(3, n + 1): ret = f_1 + f_2 f_1 = f_2 f_2 = ret return ret # entry: http://www.lintcode.com/zh-cn/problem/fibonacci/