leetcode731 我的日程表安排II

思路：

动态开点线段树，这里维护了区间最大值和区间加一个值。

实现：

 1 class SegmentTree {
 2 public:
 3     int N = (int)1e9;
 4     class Node {
 5     public:
 6         // ls 和 rs 分别代表当前区间的左右子节点
 7         Node*ls=nullptr, *rs=nullptr;
 8         // val 代表当前区间的最大高度，add 为懒标记
 9         int val=0, add=0;
10         Node(){}
11     };
12     Node*root = nullptr;
13     SegmentTree(int n){
14         root=new Node();
15         N=n;
16     }
17     void update(int l,int r,int v){
18         _update(root,0,N,l,r,v);
19     }
20     void _update(Node*node, int lc, int rc, int l, int r, int v) {
21         if (l <= lc && rc <= r) {
22             node->add += v;
23             node->val += v;
24             return ;
25         }
26         pushdown(node);
27         int mid = lc + rc >> 1;
28         if (l <= mid) _update(node->ls, lc, mid, l, r, v);
29         if (r > mid) _update(node->rs, mid + 1, rc, l, r, v);
30         pushup(node);
31     }
32     int query(int l,int r){
33         return _query(root,0,N,l,r);
34     }
35     int _query(Node*node, int lc, int rc, int l, int r) {
36         if (l <= lc && rc <= r) return node->val;
37         pushdown(node);
38         int mid = lc + rc >> 1, ans = 0;
39         if (l <= mid) ans = _query(node->ls, lc, mid, l, r);
40         if (r > mid) ans = max(ans, _query(node->rs, mid + 1, rc, l, r));
41         return ans;
42     }
43     void pushdown(Node*node) {
44         if (node->ls == nullptr) node->ls = new Node();
45         if (node->rs == nullptr) node->rs = new Node();
46         if (node->add == 0) return ;
47         node->ls->add += node->add; node->rs->add += node->add;
48         node->ls->val += node->add; node->rs->val += node->add;
49         node->add = 0;
50     }
51     void pushup(Node*node) {
52         node->val = max(node->ls->val, node->rs->val);
53     }
54 
55 };
56 class MyCalendarTwo{
57 public:
58     SegmentTree*st=NULL;
59     MyCalendarTwo() {
60         st=new SegmentTree(1e9);
61     }
62 
63     bool book(int start, int end) {
64         int maxn=st->query(start,end-1);
65         if(maxn>=2){
66             return false;
67         }
68         st->update(start,end-1,1);
69         return true;
70 
71     }
72 };

标签：node,Node,日程表,int,rs,II,add,ls,leetcode731
来源： https://www.cnblogs.com/wangyiming/p/16492966.html