算法图解(二分查找)
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2022-05-05 17:38:02
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二分查找需要有序列表
def binary_search(list,item):
"""二分查询位置,需要有序列表"""
low = 0
high = len(list) - 1
while low <= high:
mid = int((low + high) / 2)
#不为偶数自动向下园整
guess = list[mid]
if guess == item:
return mid
if guess < item:
low = mid + 1
#加1的作用是不算mid,因为第一个条件已经判断了mid值
else:
high = mid - 1
return None
my_list = [1,3,5,7,9,11,13]
print(binary_search(my_list, 11))
时间复杂度O(log n)