Submission #419978

#	Submission time	Handle	Problem	Language	Result	Execution time	Memory
419978	2021-06-07T20:36:59 Z	nafis_shifat	Meetings 2 (JOI21_meetings2)	C++14	100 / 100	439 ms	44516 KB

meetings2

#include<bits/stdc++.h>
#define ll long long
#define pii pair<int,int>
using namespace std;
const int mxn=2e5+5;
const int inf=1e9;

vector<int> adj[mxn];
int sz[mxn];
int parent[20][mxn];
int level[mxn] = {};

int n;

vector<int> con[mxn];


void dfs(int cur,int prev) {
	parent[0][cur] = prev;
	level[cur] = level[prev] + 1;
	sz[cur] = 1;
	for(int u : adj[cur]) {
		if(u == prev) continue;
		dfs(u,cur);
		sz[cur] += sz[u];
	}

	con[sz[cur]].push_back(cur);

}

int getCentroid(int cur,int prev) {
	bool f = (n - sz[cur]) <= n / 2;


	for(int u : adj[cur]) {
		if(u == prev) continue;
		f = f && (sz[u] <= (n  / 2));
	}
	if(f) return cur;


	for(int u : adj[cur]) {
		if(u == prev) continue;
		if(sz[u] > (n / 2)) return getCentroid(u,cur);
	}
	return -1;

}



int getLCA(int u,int v) {
	if(level[u] < level[v]) swap(u,v);

	int dif = level[u] - level[v];
	for(int i = 0; i < 20; i++) {
		if((dif >> i) & 1) u = parent[i][u];
	}

	if(u == v) return u;

	for(int i = 19; i >= 0; i--) {
		if(parent[i][u] != parent[i][v]) {
			u = parent[i][u];
			v = parent[i][v];
		}
	}
	return parent[0][u];
}


int dist(int u,int v) {
	return level[u] + level[v] - 2 * level[getLCA(u,v)];
}

int main() {
	cin >> n;

	for(int i = 1; i < n; i++) {
		int u,v;
		scanf("%d%d",&u,&v);
		adj[u].push_back(v);
		adj[v].push_back(u);
	}

	dfs(1,0);

	int root = getCentroid(1,0);


	for(int i = 0; i <= n; i++) con[i].clear();

	dfs(root,0);





	for(int i = 1; i < 20; i++) {
		for(int j = 1; j <= n; j++) {
			parent[i][j] = parent[i - 1][parent[i - 1][j]];
		}
	}


	int U = root , V = root;

	int res[n + 1];


	for(int i = n; i >= 1; i--) {
		int ans = dist(U,V);
		if(i % 2 == 1) {
			res[i] = 0;
			continue;
		}


		int x = i/2;

		for(int cur : con[x]) {
			int d1 = dist(U,V);
			int d2 = dist(U,cur);
			int d3 = dist(V,cur);

			if(d2 >= max(d1,d3)) {
				V = cur;
			} else if(d3 >= max(d1,d2)) {
				U = cur;
			}
			if(level[U] < level[V]) swap(U,V);
			ans = max(ans,max({d1,d2,d3}));
		}

		res[i] = ans;

		
	}

	for(int i = 1; i <= n; i++) printf("%d\n",res[i] + 1);






	
}

Compilation message

meetings2.cpp: In function 'int main()':
meetings2.cpp:82:8: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   82 |   scanf("%d%d",&u,&v);
      |   ~~~~~^~~~~~~~~~~~~~

Subtask #1
4.0 / 4.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	6 ms	9804 KB	Output is correct
2	Correct	6 ms	9708 KB	Output is correct
3	Correct	5 ms	9804 KB	Output is correct
4	Correct	6 ms	9804 KB	Output is correct
5	Correct	6 ms	9804 KB	Output is correct
6	Correct	6 ms	9804 KB	Output is correct
7	Correct	5 ms	9804 KB	Output is correct
8	Correct	6 ms	9720 KB	Output is correct
9	Correct	5 ms	9804 KB	Output is correct
10	Correct	6 ms	9804 KB	Output is correct
11	Correct	5 ms	9804 KB	Output is correct
12	Correct	6 ms	9804 KB	Output is correct
13	Correct	6 ms	9804 KB	Output is correct
14	Correct	6 ms	9804 KB	Output is correct
15	Correct	6 ms	9804 KB	Output is correct
16	Correct	6 ms	9772 KB	Output is correct
17	Correct	7 ms	9808 KB	Output is correct
18	Correct	5 ms	9768 KB	Output is correct
19	Correct	6 ms	9804 KB	Output is correct
20	Correct	6 ms	9804 KB	Output is correct
21	Correct	6 ms	9804 KB	Output is correct

Subtask #2
16.0 / 16.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	6 ms	9804 KB	Output is correct
2	Correct	6 ms	9708 KB	Output is correct
3	Correct	5 ms	9804 KB	Output is correct
4	Correct	6 ms	9804 KB	Output is correct
5	Correct	6 ms	9804 KB	Output is correct
6	Correct	6 ms	9804 KB	Output is correct
7	Correct	5 ms	9804 KB	Output is correct
8	Correct	6 ms	9720 KB	Output is correct
9	Correct	5 ms	9804 KB	Output is correct
10	Correct	6 ms	9804 KB	Output is correct
11	Correct	5 ms	9804 KB	Output is correct
12	Correct	6 ms	9804 KB	Output is correct
13	Correct	6 ms	9804 KB	Output is correct
14	Correct	6 ms	9804 KB	Output is correct
15	Correct	6 ms	9804 KB	Output is correct
16	Correct	6 ms	9772 KB	Output is correct
17	Correct	7 ms	9808 KB	Output is correct
18	Correct	5 ms	9768 KB	Output is correct
19	Correct	6 ms	9804 KB	Output is correct
20	Correct	6 ms	9804 KB	Output is correct
21	Correct	6 ms	9804 KB	Output is correct
22	Correct	9 ms	10316 KB	Output is correct
23	Correct	10 ms	10248 KB	Output is correct
24	Correct	9 ms	10316 KB	Output is correct
25	Correct	9 ms	10308 KB	Output is correct
26	Correct	9 ms	10316 KB	Output is correct
27	Correct	9 ms	10316 KB	Output is correct
28	Correct	10 ms	10316 KB	Output is correct
29	Correct	9 ms	10316 KB	Output is correct
30	Correct	9 ms	10316 KB	Output is correct
31	Correct	9 ms	10308 KB	Output is correct
32	Correct	10 ms	10444 KB	Output is correct
33	Correct	10 ms	10408 KB	Output is correct
34	Correct	9 ms	10316 KB	Output is correct
35	Correct	9 ms	10340 KB	Output is correct
36	Correct	9 ms	10316 KB	Output is correct
37	Correct	8 ms	10332 KB	Output is correct
38	Correct	9 ms	10384 KB	Output is correct

Subtask #3
80.0 / 80.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	6 ms	9804 KB	Output is correct
2	Correct	6 ms	9708 KB	Output is correct
3	Correct	5 ms	9804 KB	Output is correct
4	Correct	6 ms	9804 KB	Output is correct
5	Correct	6 ms	9804 KB	Output is correct
6	Correct	6 ms	9804 KB	Output is correct
7	Correct	5 ms	9804 KB	Output is correct
8	Correct	6 ms	9720 KB	Output is correct
9	Correct	5 ms	9804 KB	Output is correct
10	Correct	6 ms	9804 KB	Output is correct
11	Correct	5 ms	9804 KB	Output is correct
12	Correct	6 ms	9804 KB	Output is correct
13	Correct	6 ms	9804 KB	Output is correct
14	Correct	6 ms	9804 KB	Output is correct
15	Correct	6 ms	9804 KB	Output is correct
16	Correct	6 ms	9772 KB	Output is correct
17	Correct	7 ms	9808 KB	Output is correct
18	Correct	5 ms	9768 KB	Output is correct
19	Correct	6 ms	9804 KB	Output is correct
20	Correct	6 ms	9804 KB	Output is correct
21	Correct	6 ms	9804 KB	Output is correct
22	Correct	9 ms	10316 KB	Output is correct
23	Correct	10 ms	10248 KB	Output is correct
24	Correct	9 ms	10316 KB	Output is correct
25	Correct	9 ms	10308 KB	Output is correct
26	Correct	9 ms	10316 KB	Output is correct
27	Correct	9 ms	10316 KB	Output is correct
28	Correct	10 ms	10316 KB	Output is correct
29	Correct	9 ms	10316 KB	Output is correct
30	Correct	9 ms	10316 KB	Output is correct
31	Correct	9 ms	10308 KB	Output is correct
32	Correct	10 ms	10444 KB	Output is correct
33	Correct	10 ms	10408 KB	Output is correct
34	Correct	9 ms	10316 KB	Output is correct
35	Correct	9 ms	10340 KB	Output is correct
36	Correct	9 ms	10316 KB	Output is correct
37	Correct	8 ms	10332 KB	Output is correct
38	Correct	9 ms	10384 KB	Output is correct
39	Correct	339 ms	35216 KB	Output is correct
40	Correct	337 ms	34604 KB	Output is correct
41	Correct	332 ms	35308 KB	Output is correct
42	Correct	376 ms	35568 KB	Output is correct
43	Correct	345 ms	35516 KB	Output is correct
44	Correct	351 ms	35648 KB	Output is correct
45	Correct	439 ms	40704 KB	Output is correct
46	Correct	292 ms	44516 KB	Output is correct
47	Correct	337 ms	35908 KB	Output is correct
48	Correct	267 ms	35988 KB	Output is correct
49	Correct	333 ms	36100 KB	Output is correct
50	Correct	304 ms	36048 KB	Output is correct
51	Correct	268 ms	43564 KB	Output is correct

Submission #419978

Compilation message

Subtask #1 4.0 / 4.0

Subtask #2 16.0 / 16.0

Subtask #3 80.0 / 80.0

Subtask #1
4.0 / 4.0

Subtask #2
16.0 / 16.0

Subtask #3
80.0 / 80.0