今天面试一个小伙问旋转数组的二分搜索，https://leetcode.cn/problems/search-in-rotated-sorted-array 我自己先写了一份代码如下，是不是觉得很丑陋，重复代码较多？
class Solution:
def search(self, nums: List[int], target: int) -> int:
n = len(nums)
def search_highest():
l, r = 0, n - 1
while l + 1 < r:
mid = (l + r) // 2
if nums[mid] > nums[0]:
l = mid
else:
r = mid
if nums[l] > nums[r]:
return l
return r
def bin_search(l, r):
if l > r:
return -1
while l + 1 < r:
mid = (l + r) // 2
if nums[mid] < target:
l = mid
else:
r = mid
if nums[l] == target:
return l
if nums[r] == target:
return r
return -1
index = search_highest()
i = bin_search(0, index)
return i if i >= 0 else bin_search(index+1, n-1)
重构后的代码如下，看起来优雅多了，核心是lambda函数的巧妙应用！
class Solution:
def search(self, nums: List[int], target: int) -> int:
n = len(nums)
cmp_func = lambda mid: nums[mid] > nums[0]
cmp_func2 = lambda mid: nums[mid] < target
ret_func = lambda l, r: l if nums[l] > nums[r] else r
ret_func2 = lambda l, r: l if nums[l] == target else (r if nums[r] == target else -1)
def bin_search(l, r, cmp, ret):
if l > r:
return -1
while l + 1 < r:
mid = (l + r) // 2
if cmp(mid):
l = mid
else:
r = mid
return ret(l, r)
index = bin_search(0, n-1, cmp_func, ret_func)
i = bin_search(0, index, cmp_func2, ret_func2)
return i if i >= 0 else bin_search(index + 1, n - 1, cmp_func2, ret_func2)
标签：二分,重构,search,return,target,nums,代码,mid,else From： https://www.cnblogs.com/bonelee/p/17161799.html