并列递进
moreover, in addition, furthermore, besides, likewise, also, then, additionally
转折
not, yet, however, nevertheless, nonetheless, meanwhile, on the other hand, on the contrary, conversely, paradoxically, by contrast, in spite of，rather than, instead of, unfortunately
解释
in other words, in fact, as a matter of fact, that is, namely, in simpler terms
对比比较
Likewise, Similarly, In parallel to, while, whereas,
原因
because, because of, as, since, owing to, due to, thanks to, for this reason
给你一个会议时间安排的数组 intervals ，每个会议时间都会包括开始和结束的时间 intervals[i] = [starti, endi] ，返回 所需会议室的最小数量 。
示例 1：
输入：intervals = [[0,30],[5,10],[15,20]] 输出：2
示例 2：
输入：intervals = [[7,10],[2,4]] 输出：1
提示：
1 <= intervals.length <= 104 0 <= starti < endi <= 106
解题思路 我们可以想象把这些interval给叠起来，所需要会议室的最小数量就等于最大重叠的interval的数目。
转化为上下车问题，每个interval的开始时间+1，每个interval的结束时间-1，然后我们统计counter的最大数值。
换个思路就是我们以时间为单位，我们可以知道每个单位时间车上的总人数是增加多少还是减少多少，这样我们可以直接求和从开始扫描到结束，获取当前车上最大的人数就可以。
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 class Solution(object): def minMeetingRooms(self, intervals): """ :type intervals: List[List[int]] :rtype: int """ dic={} for interval in intervals: try: dic[interval[0]]+=1 except: dic[interval[0]]=1 try: dic[interval[1]]-=1 except: dic[interval[1]]=-1 max_=0 count=0 for key in sorted(dic.
Given the root node of a binary search tree and two integers low and high, return the sum of values of all nodes with a value in the inclusive range [low, high].
Example 1:
1 2 3 Input: root = [10,5,15,3,7,null,18], low = 7, high = 15 Output: 32 Explanation: Nodes 7, 10, and 15 are in the range [7, 15]. 7 + 10 + 15 = 32. Example 2:
