My Calendar III

Implement a MyCalendarThree class to store your events. A new event can always be added.

Your class will have one method, book(int start, int end). Formally, this represents a booking on the half open interval [start, end), the range of real numbers x such that start <= x < end.

A K-booking happens when K events have some non-empty intersection (ie., there is some time that is common to all K events.)

For each call to the method MyCalendar.book, return an integer K representing the largest integer such that there exists a K-booking in the calendar.Your class will be called like this: MyCalendarThree cal = new MyCalendarThree(); MyCalendarThree.book(start, end)

Example 1:

MyCalendarThree();
MyCalendarThree.book(10, 20); // returns 1
MyCalendarThree.book(50, 60); // returns 1
MyCalendarThree.book(10, 40); // returns 2
MyCalendarThree.book(5, 15); // returns 3
MyCalendarThree.book(5, 10); // returns 3
MyCalendarThree.book(25, 55); // returns 3
Explanation: 
The first two events can be booked and are disjoint, so the maximum K-booking is a 1-booking.
The third event [10, 40) intersects the first event, and the maximum K-booking is a 2-booking.
The remaining events cause the maximum K-booking to be only a 3-booking.
Note that the last event locally causes a 2-booking, but the answer is still 3 because
eg. [10, 20), [10, 40), and [5, 15) are still triple booked.

Note:

• The number of calls to MyCalendarThree.book per test case will be at most 400.

• In calls to MyCalendarThree.book(start, end), start and end are integers in the range [0, 10^9].

sweep line

和meeting room II 一样，start, end分成2个点加入arr， sort后遍历，得到最大的maxcnt

class MyCalendarThree:

    def __init__(self):
        self.arr = collections.Counter()
        

    def book(self, start: int, end: int) -> int:
        self.arr[start] += 1
        self.arr[end] -= 1
        
        res = cnt = 0
        for k in sorted(self.arr):
            cnt += self.arr[k]
            res = max(res, cnt)
        return res
        
        


# Your MyCalendarThree object will be instantiated and called as such:
# obj = MyCalendarThree()
# param_1 = obj.book(start,end)

线段树

Python 13 Lines Segment Tree with Lazy Propagation O(1) time - My Calendar III - LeetCodeLeetCode

这里直接

self.seg[ID] = self.lazy[ID] + max(self.seg[2*ID], self.seg[2*ID+1])

query结果也是返回root

self.seg[1] + self.lazy[1]

没有pushdown

class MyCalendarThree:

    def __init__(self):
        self.tree = collections.defaultdict(int) #一定要加int,否则出错
        self.lazy = collections.defaultdict(int)
        

    def book(self, start: int, end: int) -> int:
        def update(s,e,l=0,r=10**9,ID=1):
            if r <= s or e <= l: return 
            if s<=l and r<=e:
                self.tree[ID] += 1
                self.lazy[ID] += 1
            else:
                m = (l+r)//2
                update(s,e,l,m,ID<<1)
                update(s,e,m,r,ID<<1|1)
                self.tree[ID] = self.lazy[ID] + max(self.tree[ID<<1],self.tree[ID<<1|1])
            # return self.tree[ID]
        update(start,end)
        return self.tree[1]+self.lazy[1]
        
        
        
        


# Your MyCalendarThree object will be instantiated and called as such:
# obj = MyCalendarThree()
# param_1 = obj.book(start,end)