oj.uz

Submission #595727

# Submission time Handle Problem Language Result Execution time Memory
595727 2022-07-14T03:57:38 Z penguinhacker Meetings 2 (JOI21_meetings2) C++17
20 / 100
 4000 ms 67880 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 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());

	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]});
			if (it!=active.begin()) {
				--it;
				int v=(*it)[1];
				if (ia(v, u)) {
					upd(tin[v], 0);
					active.erase(it);
				}
			}
			upd(tin[u], 1);
			active.insert({tin[u], u});
			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]});
			bool fine=1;
			if (it!=highest.begin()) {
				--it;
				int v=(*it)[1];
				fine=!ia(v, u);
			}
			if (fine) {
				for (it=highest.lower_bound({tin[u]}); it!=highest.end()&&ia(u, (*it)[1]); it=highest.erase(it));
				highest.insert({tin[u], u});
			}
		}
		//cout << i << " " << best << endl;
		for (ar<int, 2> x : active)
			for (ar<int, 2> y : highest)
				if (ia(y[1], x[1]))
					best=max(best, d[x[1]]-d[y[1]]+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:94:19: warning: comparison of integer expressions of different signedness: 'std::vector<int>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   94 |  assert(stk.size()==2*n-1);
      |         ~~~~~~~~~~^~~~~~~

Subtask #1
4.0 / 4.0

# Verdict Execution time Memory Grader output
1 Correct 4 ms 4948 KB Output is correct
2 Correct 3 ms 4948 KB Output is correct
3 Correct 2 ms 4948 KB Output is correct
4 Correct 2 ms 4964 KB Output is correct
5 Correct 3 ms 4948 KB Output is correct
6 Correct 2 ms 4948 KB Output is correct
7 Correct 3 ms 4948 KB Output is correct
8 Correct 4 ms 4948 KB Output is correct
9 Correct 2 ms 4948 KB Output is correct
10 Correct 2 ms 4948 KB Output is correct
11 Correct 2 ms 4948 KB Output is correct
12 Correct 2 ms 4948 KB Output is correct
13 Correct 2 ms 4948 KB Output is correct
14 Correct 3 ms 4948 KB Output is correct
15 Correct 3 ms 4948 KB Output is correct
16 Correct 2 ms 4948 KB Output is correct
17 Correct 3 ms 4948 KB Output is correct
18 Correct 3 ms 4948 KB Output is correct
19 Correct 3 ms 4948 KB Output is correct
20 Correct 3 ms 4948 KB Output is correct
21 Correct 3 ms 4948 KB Output is correct

Subtask #2
16.0 / 16.0

# Verdict Execution time Memory Grader output
1 Correct 4 ms 4948 KB Output is correct
2 Correct 3 ms 4948 KB Output is correct
3 Correct 2 ms 4948 KB Output is correct
4 Correct 2 ms 4964 KB Output is correct
5 Correct 3 ms 4948 KB Output is correct
6 Correct 2 ms 4948 KB Output is correct
7 Correct 3 ms 4948 KB Output is correct
8 Correct 4 ms 4948 KB Output is correct
9 Correct 2 ms 4948 KB Output is correct
10 Correct 2 ms 4948 KB Output is correct
11 Correct 2 ms 4948 KB Output is correct
12 Correct 2 ms 4948 KB Output is correct
13 Correct 2 ms 4948 KB Output is correct
14 Correct 3 ms 4948 KB Output is correct
15 Correct 3 ms 4948 KB Output is correct
16 Correct 2 ms 4948 KB Output is correct
17 Correct 3 ms 4948 KB Output is correct
18 Correct 3 ms 4948 KB Output is correct
19 Correct 3 ms 4948 KB Output is correct
20 Correct 3 ms 4948 KB Output is correct
21 Correct 3 ms 4948 KB Output is correct
22 Correct 11 ms 5996 KB Output is correct
23 Correct 11 ms 5972 KB Output is correct
24 Correct 11 ms 6056 KB Output is correct
25 Correct 10 ms 5972 KB Output is correct
26 Correct 11 ms 5996 KB Output is correct
27 Correct 10 ms 5972 KB Output is correct
28 Correct 11 ms 5972 KB Output is correct
29 Correct 10 ms 6068 KB Output is correct
30 Correct 11 ms 5996 KB Output is correct
31 Correct 10 ms 6068 KB Output is correct
32 Correct 9 ms 6100 KB Output is correct
33 Correct 8 ms 6228 KB Output is correct
34 Correct 73 ms 6100 KB Output is correct
35 Correct 93 ms 6276 KB Output is correct
36 Correct 12 ms 6088 KB Output is correct
37 Correct 91 ms 6144 KB Output is correct
38 Correct 10 ms 6164 KB Output is correct

Subtask #3
0 / 80.0

# Verdict Execution time Memory Grader output
1 Correct 4 ms 4948 KB Output is correct
2 Correct 3 ms 4948 KB Output is correct
3 Correct 2 ms 4948 KB Output is correct
4 Correct 2 ms 4964 KB Output is correct
5 Correct 3 ms 4948 KB Output is correct
6 Correct 2 ms 4948 KB Output is correct
7 Correct 3 ms 4948 KB Output is correct
8 Correct 4 ms 4948 KB Output is correct
9 Correct 2 ms 4948 KB Output is correct
10 Correct 2 ms 4948 KB Output is correct
11 Correct 2 ms 4948 KB Output is correct
12 Correct 2 ms 4948 KB Output is correct
13 Correct 2 ms 4948 KB Output is correct
14 Correct 3 ms 4948 KB Output is correct
15 Correct 3 ms 4948 KB Output is correct
16 Correct 2 ms 4948 KB Output is correct
17 Correct 3 ms 4948 KB Output is correct
18 Correct 3 ms 4948 KB Output is correct
19 Correct 3 ms 4948 KB Output is correct
20 Correct 3 ms 4948 KB Output is correct
21 Correct 3 ms 4948 KB Output is correct
22 Correct 11 ms 5996 KB Output is correct
23 Correct 11 ms 5972 KB Output is correct
24 Correct 11 ms 6056 KB Output is correct
25 Correct 10 ms 5972 KB Output is correct
26 Correct 11 ms 5996 KB Output is correct
27 Correct 10 ms 5972 KB Output is correct
28 Correct 11 ms 5972 KB Output is correct
29 Correct 10 ms 6068 KB Output is correct
30 Correct 11 ms 5996 KB Output is correct
31 Correct 10 ms 6068 KB Output is correct
32 Correct 9 ms 6100 KB Output is correct
33 Correct 8 ms 6228 KB Output is correct
34 Correct 73 ms 6100 KB Output is correct
35 Correct 93 ms 6276 KB Output is correct
36 Correct 12 ms 6088 KB Output is correct
37 Correct 91 ms 6144 KB Output is correct
38 Correct 10 ms 6164 KB Output is correct
39 Correct 916 ms 59704 KB Output is correct
40 Correct 797 ms 59392 KB Output is correct
41 Correct 784 ms 60016 KB Output is correct
42 Correct 812 ms 60544 KB Output is correct
43 Correct 912 ms 60608 KB Output is correct
44 Correct 947 ms 60548 KB Output is correct
45 Correct 1801 ms 65156 KB Output is correct
46 Correct 433 ms 67880 KB Output is correct
47 Execution timed out 4056 ms 62400 KB Time limit exceeded
48 Halted 0 ms 0 KB -