python实现Fibonacci和二分法

最简单的实现Fabonacci代码：

def Fibonacci(n):
if n <= 1:
return 1
else:
return Fibonacci(n-1) + Fibonacci(n-2)

我们可以用一个数组存储，牺牲空间换取时间，避免多次无效求值

代码def BinarySearch(numbers,x,n):
left = 0;right = n - 1
while(left <= right):
middle = (left + right)/2
if numbers[middle] == x:
return middle + 1
elif numbers[middle] > x:
right = middle-1
else:
left = middle + 1
else:
return -1