【python】二分查找算法

nums = [-1, 1,2,3]
target = 3
class Solution:
  #定義全局變量，記錄右邊一半時的偏移量
global num_count
num_count = 0
def search(self, nums, target):
global num_count
if int(len(nums)) == 0:
return -1
elif target in nums:
mid = int(len(nums) / 2)
if nums[mid] == target:
  //最後返回時，需要加上右邊的偏移量
return mid+num_count
elif nums[mid] > target:
new_nums = nums[0:mid]
return self.search(new_nums, target)
elif nums[mid] < target:
  //左邊不需要加，右邊需要加上偏移量
num_count += mid
new_nums = nums[mid:int(len(nums))]
return self.search(new_nums, target)
else:
return -1
else:
return -1
aa = Solution()
bb = aa.search(nums, target)
print(bb)