题解 | #数字在升序数组中出现的次数#

思路：强行使用二分查找方法 1、二分查找找最左k，二分查找找最右k 2、位置间距离既为答案

class Solution:
    def GetNumberOfK(self , data: List[int], k: int) -> int:
        if k not in data:
            return 0
        if len(data) <= 1:
            return len(data)
        
        left_index = self.get_left_k(data, k)
        right_index = self.get_right_k(data, k)
        return right_index - left_index + 1
        
    def get_left_k(self, data, k):
        
        if k not in data:
            return 0
        
        l = 0
        r = len(data) - 1
        
        while l + 1 < r:
            mid = (l + r) // 2 
            
            if data[mid] >= k: #找最左右先行
                r = mid
            else:
                l = mid

        if data[l] == k: #结果先判断左
            return l 
        if data[r] == k:
            return r 
        
    def get_right_k(self, data, k):
        
        if k not in data:
            return 0
        
        l = 0
        r = len(data) - 1
        
        while l + 1 < r:
            mid = (l + r) // 2
            
            if data[mid] <= k: #找最右左先行
                l = mid
            else:
                r = mid

        if data[r] == k: #结果先判断右
            return r 
        if data[l] == k:
            return l