1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
|
struct Seg{
int mi, ma, v;
Seg* left, *right;
Seg(vector<int>& A, int l, int r): mi(A[l]), ma(A[r]), v(0), left(nullptr), right(nullptr) {
if(l != r) {
int m = l + (r - l) / 2;
left = new Seg(A,l,m);
right = new Seg(A,m+1,r);
}
}
void update(int n, int k) {
if(mi <= n and n <= ma) {
v = max(v, k);
if(left) left->update(n,k);
if(right) right->update(n,k);
}
}
int query(int n) {
if(ma < n) return v;
if(mi >= n) return 0;
return max(left ? left->query(n) : 0, right ? right->query(n) : 0);
}
};
int Solution::solve(vector<vector<int> > &A) {
vector<int> S;
for(auto vec : A) S.push_back(vec[1]);
sort(begin(S), end(S));
S.erase(unique(begin(S), end(S)), end(S));
Seg* seg = new Seg(S,0,S.size() - 1);
int res = 0;
for(auto vec : A) {
auto a = vec[0], b = vec[1];
int now = seg->query(a);
res = max(res, now + 1);
seg->update(b, now + 1);
}
return res;
}
|
