oj.uz

Submission #595729

# Submission time Handle Problem Language Result Execution time Memory
595729 2022-07-14T04:13:11 Z penguinhacker Meetings 2 (JOI21_meetings2) C++17
100 / 100
 930 ms 79200 KB 
#include <bits/stdc++.h>
using namespace std;
 
#define ll long long
#define ar array
 
const int mxN=2e5, INF=1e9;
int n, d[mxN], s[mxN], anc[mxN][18], ans[mxN+1], tin[mxN], tout[mxN];
vector<int> adj[mxN], stk;
set<ar<int, 2>> active, highest;
 
void dfs(int u=0) {
	s[u]=1;
	tin[u]=stk.size();
	stk.push_back(d[u]);
	for (int i=1; i<18; ++i)
		anc[u][i]=anc[anc[u][i-1]][i-1];
	for (int v : adj[u])
		if (v!=anc[u][0]) {
			d[v]=d[u]+1, anc[v][0]=u;
			dfs(v);
			s[u]+=s[v];
			stk.push_back(d[u]);
		}
	tout[u]=stk.size()-1;
}

bool ia(int u, int v) {
	return tin[u]<=tin[v]&&tout[v]<=tout[u];
}
 
int lca(int u, int v) {
	if (ia(u, v)||ia(v, u))
		return ia(u, v)?u:v;
	for (int i=17; ~i; --i)
		if (!ia(anc[u][i], v))
			u=anc[u][i];
	return anc[u][0];
}
 
int dist(int u, int v) {
	return d[u]+d[v]-2*d[lca(u, v)];
}

struct Node {
	int ans, mn, mx, lhs, rhs;
} st[1<<20];
 
Node cmb(Node a, Node b) {
	return {
		max({a.ans, b.ans, a.rhs+b.mx, a.mx+b.lhs}),
		min(a.mn, b.mn),
		max(a.mx, b.mx),
		max({a.lhs, b.lhs, -2*a.mn+b.mx}),
		max({a.rhs, b.rhs, a.mx-2*b.mn})
	};
}
 
void bld(int u=1, int l=0, int r=2*n-2) {
	if (l==r) {
		st[u].mn=stk[l];
		st[u].mx=st[u].lhs=st[u].rhs=-INF;
		return;
	}
	int mid=(l+r)/2;
	bld(2*u, l, mid);
	bld(2*u+1, mid+1, r);
	st[u]=cmb(st[2*u], st[2*u+1]);
}
 
void upd(int i, bool on, int u=1, int l=0, int r=2*n-2) {
	if (l==r) {
		//cout << "activating " << i << " " << on << endl;
		st[u].mx=on?stk[l]:-INF;
		st[u].lhs=st[u].rhs=on?-stk[l]:-INF;
		return;
	}
	int mid=(l+r)/2;
	i<=mid?upd(i, on, 2*u, l, mid):upd(i, on, 2*u+1, mid+1, r);
	st[u]=cmb(st[2*u], st[2*u+1]);
}

int before(set<ar<int, 2>>& nodes, int u) {
	auto it=nodes.lower_bound({tin[u]});
	if (it!=nodes.begin()) {
		int v=(*prev(it))[1];
		return ia(v, u)?v:-1;
	}
	return -1;
}

struct Boring_Old_Range_Max_Segment_Tree_Ugh {
	int st[1<<20];
	void upd(int i, int x, int u=1, int l=0, int r=2*n-2) {
		if (l==r) { st[u]=x; return; }
		int mid=(l+r)/2;
		i<=mid?upd(i, x, 2*u, l, mid):upd(i, x, 2*u+1, mid+1, r);
		st[u]=max(st[2*u], st[2*u+1]);
	}
	int qry(int ql, int qr, int u=1, int l=0, int r=2*n-2) {
		if (l>qr||r<ql) return 0;
		if (ql<=l&&r<=qr) return st[u];
		int mid=(l+r)/2;
		return max(qry(ql, qr, 2*u, l, mid), qry(ql, qr, 2*u+1, mid+1, r));
	}
} st_max;

int main() {
	ios::sync_with_stdio(0);
	cin.tie(0);
	cin >> n;
	for (int i=1; i<n; ++i) {
		int u, v;
		cin >> u >> v, --u, --v;
		adj[u].push_back(v);
		adj[v].push_back(u);
	}
	dfs();
	assert(stk.size()==2*n-1);
	bld();

	vector<ar<int, 2>> subtrees, uptrees;
	for (int i=1; i<n; ++i) {
		subtrees.push_back({s[i], i});
		uptrees.push_back({n-s[i], i});
	}
	sort(subtrees.begin(), subtrees.end());
	sort(uptrees.begin(), uptrees.end());

	memset(st_max.st, -1, sizeof(st_max.st));
	fill(ans, ans+n+1, 1);
	int best=1;
	for (int i=n/2; i; --i) {
		while(subtrees.size()&&subtrees.back()[0]>=i) {
			int u=subtrees.back()[1];
			subtrees.pop_back();
			auto it=active.lower_bound({tin[u]});
			int v=before(active, u);
			if (v!=-1) {
				upd(tin[v], 0);
				active.erase({tin[v], v});
			}
			upd(tin[u], 1);
			active.insert({tin[u], u});
			st_max.upd(tin[u], d[u]);
			v=before(highest, u);
			if (v!=-1)
				best=max(best, d[u]-d[v]+2);
			if (highest.find({tin[u], u})!=highest.end())
				best=max(best, 2);
		}
		best=max(best, st[1].ans+1);
		while(uptrees.size()&&uptrees.back()[0]>=i) {
			int u=uptrees.back()[1];
			uptrees.pop_back();
			auto it=highest.lower_bound({tin[u]});
			if (before(highest, u)==-1) {
				for (it=highest.lower_bound({tin[u]}); it!=highest.end()&&ia(u, (*it)[1]); it=highest.erase(it));
				highest.insert({tin[u], u});
				best=max(best, st_max.qry(tin[u], tout[u])-d[u]+2);
			}
		}
		ans[2*i]=best;
	}
	for (int i=1; i<=n; ++i)
		cout << ans[i] << "\n";
	return 0;
}

Compilation message

In file included from /usr/include/c++/10/cassert:44,
                 from /usr/include/x86_64-linux-gnu/c++/10/bits/stdc++.h:33,
                 from meetings2.cpp:1:
meetings2.cpp: In function 'int main()':
meetings2.cpp:119:19: warning: comparison of integer expressions of different signedness: 'std::vector<int>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
  119 |  assert(stk.size()==2*n-1);
      |         ~~~~~~~~~~^~~~~~~
meetings2.cpp:137:9: warning: variable 'it' set but not used [-Wunused-but-set-variable]
  137 |    auto it=active.lower_bound({tin[u]});
      |         ^~

Subtask #1
4.0 / 4.0

# Verdict Execution time Memory Grader output
1 Correct 5 ms 9044 KB Output is correct
2 Correct 4 ms 9044 KB Output is correct
3 Correct 4 ms 9044 KB Output is correct
4 Correct 4 ms 9044 KB Output is correct
5 Correct 4 ms 9044 KB Output is correct
6 Correct 4 ms 9044 KB Output is correct
7 Correct 4 ms 9044 KB Output is correct
8 Correct 4 ms 9052 KB Output is correct
9 Correct 4 ms 9044 KB Output is correct
10 Correct 4 ms 9044 KB Output is correct
11 Correct 5 ms 9044 KB Output is correct
12 Correct 4 ms 9044 KB Output is correct
13 Correct 4 ms 9044 KB Output is correct
14 Correct 4 ms 9044 KB Output is correct
15 Correct 4 ms 9044 KB Output is correct
16 Correct 5 ms 9152 KB Output is correct
17 Correct 5 ms 9044 KB Output is correct
18 Correct 5 ms 9132 KB Output is correct
19 Correct 5 ms 9044 KB Output is correct
20 Correct 5 ms 9044 KB Output is correct
21 Correct 4 ms 9044 KB Output is correct

Subtask #2
16.0 / 16.0

# Verdict Execution time Memory Grader output
1 Correct 5 ms 9044 KB Output is correct
2 Correct 4 ms 9044 KB Output is correct
3 Correct 4 ms 9044 KB Output is correct
4 Correct 4 ms 9044 KB Output is correct
5 Correct 4 ms 9044 KB Output is correct
6 Correct 4 ms 9044 KB Output is correct
7 Correct 4 ms 9044 KB Output is correct
8 Correct 4 ms 9052 KB Output is correct
9 Correct 4 ms 9044 KB Output is correct
10 Correct 4 ms 9044 KB Output is correct
11 Correct 5 ms 9044 KB Output is correct
12 Correct 4 ms 9044 KB Output is correct
13 Correct 4 ms 9044 KB Output is correct
14 Correct 4 ms 9044 KB Output is correct
15 Correct 4 ms 9044 KB Output is correct
16 Correct 5 ms 9152 KB Output is correct
17 Correct 5 ms 9044 KB Output is correct
18 Correct 5 ms 9132 KB Output is correct
19 Correct 5 ms 9044 KB Output is correct
20 Correct 5 ms 9044 KB Output is correct
21 Correct 4 ms 9044 KB Output is correct
22 Correct 12 ms 10068 KB Output is correct
23 Correct 13 ms 10068 KB Output is correct
24 Correct 12 ms 10068 KB Output is correct
25 Correct 13 ms 10068 KB Output is correct
26 Correct 12 ms 10068 KB Output is correct
27 Correct 12 ms 10172 KB Output is correct
28 Correct 13 ms 10172 KB Output is correct
29 Correct 14 ms 10084 KB Output is correct
30 Correct 13 ms 10068 KB Output is correct
31 Correct 13 ms 10064 KB Output is correct
32 Correct 12 ms 10272 KB Output is correct
33 Correct 15 ms 10324 KB Output is correct
34 Correct 17 ms 10196 KB Output is correct
35 Correct 15 ms 10388 KB Output is correct
36 Correct 13 ms 10192 KB Output is correct
37 Correct 13 ms 10324 KB Output is correct
38 Correct 11 ms 10196 KB Output is correct

Subtask #3
80.0 / 80.0

# Verdict Execution time Memory Grader output
1 Correct 5 ms 9044 KB Output is correct
2 Correct 4 ms 9044 KB Output is correct
3 Correct 4 ms 9044 KB Output is correct
4 Correct 4 ms 9044 KB Output is correct
5 Correct 4 ms 9044 KB Output is correct
6 Correct 4 ms 9044 KB Output is correct
7 Correct 4 ms 9044 KB Output is correct
8 Correct 4 ms 9052 KB Output is correct
9 Correct 4 ms 9044 KB Output is correct
10 Correct 4 ms 9044 KB Output is correct
11 Correct 5 ms 9044 KB Output is correct
12 Correct 4 ms 9044 KB Output is correct
13 Correct 4 ms 9044 KB Output is correct
14 Correct 4 ms 9044 KB Output is correct
15 Correct 4 ms 9044 KB Output is correct
16 Correct 5 ms 9152 KB Output is correct
17 Correct 5 ms 9044 KB Output is correct
18 Correct 5 ms 9132 KB Output is correct
19 Correct 5 ms 9044 KB Output is correct
20 Correct 5 ms 9044 KB Output is correct
21 Correct 4 ms 9044 KB Output is correct
22 Correct 12 ms 10068 KB Output is correct
23 Correct 13 ms 10068 KB Output is correct
24 Correct 12 ms 10068 KB Output is correct
25 Correct 13 ms 10068 KB Output is correct
26 Correct 12 ms 10068 KB Output is correct
27 Correct 12 ms 10172 KB Output is correct
28 Correct 13 ms 10172 KB Output is correct
29 Correct 14 ms 10084 KB Output is correct
30 Correct 13 ms 10068 KB Output is correct
31 Correct 13 ms 10064 KB Output is correct
32 Correct 12 ms 10272 KB Output is correct
33 Correct 15 ms 10324 KB Output is correct
34 Correct 17 ms 10196 KB Output is correct
35 Correct 15 ms 10388 KB Output is correct
36 Correct 13 ms 10192 KB Output is correct
37 Correct 13 ms 10324 KB Output is correct
38 Correct 11 ms 10196 KB Output is correct
39 Correct 840 ms 63792 KB Output is correct
40 Correct 842 ms 63136 KB Output is correct
41 Correct 801 ms 63864 KB Output is correct
42 Correct 833 ms 64396 KB Output is correct
43 Correct 874 ms 64388 KB Output is correct
44 Correct 833 ms 64396 KB Output is correct
45 Correct 676 ms 69004 KB Output is correct
46 Correct 522 ms 71732 KB Output is correct
47 Correct 862 ms 68172 KB Output is correct
48 Correct 930 ms 79200 KB Output is correct
49 Correct 640 ms 65236 KB Output is correct
50 Correct 889 ms 72280 KB Output is correct
51 Correct 598 ms 74060 KB Output is correct