python 代码

class Solution(object):
    def getNumberOfK(self, nums, k):
        """
        :type nums: list[int]
        :type k: int
        :rtype: int
        """
        if not nums: return 0
        l = 0
        r = len(nums) - 1
        while l < r:
            mid = (l+r) >> 1
            if nums[mid] >= k:
                r = mid
            else:
                l = mid + 1
        s1 = l
        l = 0
        r = len(nums) - 1
        while l < r:
            mid = (l+r+1) >> 1
            if nums[mid] <= k:
                l = mid
            else:
                r = mid - 1
        s2 = l
        return s2-s1+1 if nums[s1]==k and nums[s2]==k else 0