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Submission #292937

# Submission time Handle Problem Language Result Execution time Memory
292937 2020-09-07T14:53:13 Z arnold518 Spring cleaning (CEOI20_cleaning) C++14
100 / 100
 306 ms 36152 KB 
#include <bits/stdc++.h>
using namespace std;

typedef long long ll;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;

const int MAXN = 2e5;

int N, Q, M;
vector<int> adj[MAXN+10];
int dp[MAXN+10], par[MAXN+10][30], dep[MAXN+10], leaf, cnt[MAXN+10], val, root;
int L[MAXN+10], R[MAXN+10], dfn;
pii dp2[MAXN+10];

void dfs(int now, int bef, int d)
{
	L[now]=++dfn;
	par[now][0]=bef;
	dep[now]=d;
	dp[now]=0;
	if(adj[now].size()==1)
	{
		dp[now]=1;
		R[now]=dfn;
		return;
	}
	for(int nxt : adj[now])
	{
		if(nxt==bef) continue;
		dfs(nxt, now, d+1);
		dp[now]+=dp[nxt];
		dp[now]%=2;
	}
	R[now]=dfn;
}

pii operator + (const pii &p, const pii &q) { return {p.first+q.first, p.second+q.second}; }
pii operator - (const pii &p, const pii &q) { return {p.first-q.first, p.second-q.second}; }

void dfs2(int now, int bef, pii val)
{
	if(now!=bef)
	{
		if(dp[now]==0) val.first++;
		else if(dp[now]==1) val.second++;
	}
	dp2[now]=val;
	for(int nxt : adj[now])
	{
		if(nxt==bef) continue;
		dfs2(nxt, now, val);
	}
}

int lca(int u, int v)
{
	if(dep[u]>dep[v]) swap(u, v);
	for(int i=20; i>=0; i--) if(dep[par[v][i]]>=dep[u]) v=par[v][i];
	if(u==v) return u;
	for(int i=20; i>=0; i--) if(par[u][i]!=par[v][i]) u=par[u][i], v=par[v][i];
	return par[u][0];
}

int dp3[MAXN+10];
vector<int> adj2[MAXN+10];
int ans=0;

void dfs3(int now, int bef)
{
	for(int nxt : adj2[now])
	{
		if(nxt==bef) continue;
		//printf("Edge %d %d\n", nxt, now);
		dfs3(nxt, now);
		dp3[now]+=dp3[nxt];
		dp3[now]%=2;
	}
	//printf("%d : %d / %d %d\n", now, dp3[now], dp2[now].first, dp2[now].second);
	if(now!=bef)
	{
		if(dp3[now])
		{
			pii t=dp2[now]-dp2[bef];
			ans-=t.first*2+t.second;
			ans+=t.first+t.second*2;
		}
	}
}

int main()
{
	scanf("%d%d", &N, &Q);
	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);
	}

	for(int i=1; i<=N; i++) if(adj[i].size()==1) leaf++;

	for(int i=1; i<=N; i++) if(adj[i].size()!=1) { root=i; break; }
	dfs(root, root, 1);
	dfs2(root, root, pii(0, 0));
	
	for(int i=1; i<=N; i++)
	{
		if(i==root) continue;
		if(dp[i]==0) val+=2;
		else val+=1;
	}
	for(int j=1; j<=20; j++) for(int i=1; i<=N; i++) par[i][j]=par[par[i][j-1]][j-1];

	while(Q--)
	{
		scanf("%d", &M);
		vector<int> V, V2;
		for(int i=1; i<=M; i++)
		{
			int t;
			scanf("%d", &t);
			V.push_back(t);
		}

		sort(V.begin(), V.end()); V2=V;
		V2.erase(unique(V2.begin(), V2.end()), V2.end());

		int lt=leaf;
		for(auto it : V2) if(adj[it].size()==1) lt--;
		lt+=M;

		if(lt%2) { printf("-1\n"); continue; }

		for(auto it : V) cnt[it]++;

		vector<int> VV=V2;
		sort(VV.begin(), VV.end(), [&](const int &p, const int &q){ return L[p]<L[q]; });

		int t=VV.size();
		for(int i=0; i+1<t; i++) VV.push_back(lca(VV[i], VV[i+1]));
		VV.push_back(root);

		sort(VV.begin(), VV.end(), [&](const int &p, const int &q){ return L[p]<L[q]; });
		VV.erase(unique(VV.begin(), VV.end()), VV.end());

		vector<int> S;
		for(int i=0; i<VV.size(); i++)
		{
			while(!S.empty() && !(L[S.back()]<=L[VV[i]] && R[VV[i]]<=R[S.back()])) S.pop_back();
			if(!S.empty()) adj2[S.back()].push_back(VV[i]);
			S.push_back(VV[i]);
		}

		for(auto it : V2)
		{
			if(adj[it].size()==1) dp3[it]=(cnt[it]-1)%2;
			else dp3[it]=cnt[it]%2;
		}

		ans=val+M;
		dfs3(root, root);

		printf("%d\n", ans);

		for(auto it : V) cnt[it]=0;
		for(auto it : VV) adj2[it].clear();
		for(auto it : VV) dp3[it]=0;
	}
}

Compilation message

cleaning.cpp: In function 'int main()':
cleaning.cpp:149:17: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  149 |   for(int i=0; i<VV.size(); i++)
      |                ~^~~~~~~~~~
cleaning.cpp:93:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   93 |  scanf("%d%d", &N, &Q);
      |  ~~~~~^~~~~~~~~~~~~~~~
cleaning.cpp:97:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   97 |   scanf("%d%d", &u, &v);
      |   ~~~~~^~~~~~~~~~~~~~~~
cleaning.cpp:118:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  118 |   scanf("%d", &M);
      |   ~~~~~^~~~~~~~~~
cleaning.cpp:123:9: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  123 |    scanf("%d", &t);
      |    ~~~~~^~~~~~~~~~

Subtask #1
0.0 / 0.0

# Verdict Execution time Memory Grader output
1 Correct 7 ms 9728 KB Output is correct
2 Correct 102 ms 13688 KB Output is correct

Subtask #2
9.0 / 9.0

# Verdict Execution time Memory Grader output
1 Correct 32 ms 11120 KB Output is correct
2 Correct 26 ms 11128 KB Output is correct
3 Correct 93 ms 28244 KB Output is correct
4 Correct 106 ms 24128 KB Output is correct
5 Correct 150 ms 29808 KB Output is correct

Subtask #3
9.0 / 9.0

# Verdict Execution time Memory Grader output
1 Correct 32 ms 11888 KB Output is correct
2 Correct 29 ms 11776 KB Output is correct
3 Correct 116 ms 35552 KB Output is correct
4 Correct 172 ms 36152 KB Output is correct
5 Correct 112 ms 32740 KB Output is correct

Subtask #4
16.0 / 16.0

# Verdict Execution time Memory Grader output
1 Correct 67 ms 14404 KB Output is correct
2 Correct 45 ms 13568 KB Output is correct
3 Correct 23 ms 13312 KB Output is correct
4 Correct 23 ms 13824 KB Output is correct
5 Correct 31 ms 14080 KB Output is correct
6 Correct 74 ms 14200 KB Output is correct

Subtask #5
19.0 / 19.0

# Verdict Execution time Memory Grader output
1 Correct 139 ms 21880 KB Output is correct
2 Correct 198 ms 22052 KB Output is correct
3 Correct 126 ms 16052 KB Output is correct
4 Correct 178 ms 22008 KB Output is correct
5 Correct 180 ms 22008 KB Output is correct

Subtask #6
17.0 / 17.0

# Verdict Execution time Memory Grader output
1 Correct 202 ms 28380 KB Output is correct
2 Correct 208 ms 31096 KB Output is correct
3 Correct 222 ms 31224 KB Output is correct
4 Correct 205 ms 30584 KB Output is correct

Subtask #7
30.0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 7 ms 9728 KB Output is correct
2 Correct 102 ms 13688 KB Output is correct
3 Correct 32 ms 11120 KB Output is correct
4 Correct 26 ms 11128 KB Output is correct
5 Correct 93 ms 28244 KB Output is correct
6 Correct 106 ms 24128 KB Output is correct
7 Correct 150 ms 29808 KB Output is correct
8 Correct 32 ms 11888 KB Output is correct
9 Correct 29 ms 11776 KB Output is correct
10 Correct 116 ms 35552 KB Output is correct
11 Correct 172 ms 36152 KB Output is correct
12 Correct 112 ms 32740 KB Output is correct
13 Correct 67 ms 14404 KB Output is correct
14 Correct 45 ms 13568 KB Output is correct
15 Correct 23 ms 13312 KB Output is correct
16 Correct 23 ms 13824 KB Output is correct
17 Correct 31 ms 14080 KB Output is correct
18 Correct 74 ms 14200 KB Output is correct
19 Correct 139 ms 21880 KB Output is correct
20 Correct 198 ms 22052 KB Output is correct
21 Correct 126 ms 16052 KB Output is correct
22 Correct 178 ms 22008 KB Output is correct
23 Correct 180 ms 22008 KB Output is correct
24 Correct 202 ms 28380 KB Output is correct
25 Correct 208 ms 31096 KB Output is correct
26 Correct 222 ms 31224 KB Output is correct
27 Correct 205 ms 30584 KB Output is correct
28 Correct 172 ms 20984 KB Output is correct
29 Correct 204 ms 31608 KB Output is correct
30 Correct 113 ms 28144 KB Output is correct
31 Correct 161 ms 36080 KB Output is correct
32 Correct 189 ms 22108 KB Output is correct
33 Correct 272 ms 27768 KB Output is correct
34 Correct 306 ms 32120 KB Output is correct
35 Correct 304 ms 32120 KB Output is correct