力扣-数组-二分查找704

 1 class Solution(object):
 2     def search(self, nums, target):
 3         """
 4         :type nums: List[int]
 5         :type target: int
 6         :rtype: int
 7         """
 8         ## 暴力循环法
 9         # for i in range(len(nums)):
10         #     if target==nums[i]:
11         #         return i
12         #     if nums[i]>target or i==len(nums)-1:
13         #         return -1
14 
15         ## 二分查找法
16         ## 注意划分边界和终止条件，最好的方法就是实例，然后总结
17         left = 0
18         right = len(nums)-1
19    
20         while(1):
21             mid = (left+right) // 2
22             if left==right and nums[left]!=target:
23                 return -1
24             if target==nums[mid]:
25                 return mid
26             elif target<nums[mid]:
27                 right = mid
28             elif target>nums[mid]:
29                 left = mid + 1