参考答案

参考回答:

def binary_search(num_list,x):
num_list=sorted(num_list)
left, right = 0, len(num_list)
while left < right:
mid = (left + right) / 2
if num_list[mid] > x:
right = mid
elif num_list[mid] < x:
left = mid + 1
else:
return num_list[x]
return x