python实现 LeetCode34——Search for a Range

二分法找到target的位置，再判断前后的位置class Solution(object):
def searchRange(self, nums, target):
start=0
end=len(nums)-1
while start<=end and start>=0 and end<=len(nums)-1:
mid=(start+end)/2
if nums[mid]==target:
start = mid
end = mid
while start>0 and nums[start - 1] == nums[start]:
start = start - 1
while end<len(nums)-1 and nums[end] == nums[end+1]:
end = end + 1
return [start,end]
else:
if nums[mid]>target:
end=mid-1
else:
start=start+1
return [-1,-1]