oj.uz

Submission #949971

# Submission time Handle Problem Language Result Execution time Memory
949971 2024-03-20T02:04:18 Z koukirocks Love Polygon (BOI18_polygon) C++17
46 / 100
 2000 ms 35980 KB 
#include <bits/stdc++.h>
#define speed ios_base::sync_with_stdio(0); cin.tie(0)
#define all(x) (x).begin(),(x).end()
#define F first
#define S second
 
using namespace std;
typedef long long ll;
typedef double db;
typedef long double ldb;
typedef pair<int,int> pii;
typedef pair<ll,ll> pll;
 
const ll MAX=1e5+10,P=998244353;
const ll INF=0x3f3f3f3f,oo=0x3f3f3f3f3f3f3f3f;
 
int n;
vector<pair<string,string> > eg;
int G[MAX];
vector<int> cptG[MAX];
int dp[MAX][2];

void dfs(int v,int p,vector<bool>& vis,vector<bool>& tmpvis,vector<int>& ccl,int& stt) {
//	cout<<v<<" "<<p<<"\n"<<flush;
	tmpvis[v]=true;
	for (int i:cptG[v]) {
		if (i==p) {
			p=-1;
			continue;
		}
		if (tmpvis[i]) {
			stt=i;
			ccl.push_back(v);
			if (i==v) stt=-1;
			return;
		}
		dfs(i,v,vis,tmpvis,ccl,stt);
		if (stt>=-1) {
//			cout<<v<<" "<<stt<<" stt\n";
			if (stt>=0) {
				ccl.push_back(v);
				if (stt==v) stt=-1;
			}
			return;
		}
	}
	tmpvis[v]=false;
}

void dfsvis(int st,vector<bool>& vis) {
	vis[st]=true;
	queue<int> BFS;
	BFS.push(st);
	while (!BFS.empty()) {
		int v=BFS.front();
		BFS.pop();
		for (int i:cptG[v]) {
			if (!vis[i]) {
				vis[i]=true;
				BFS.push(i);
			}
		}
	}
}

void dfs2(int v,int p,vector<bool>& isccl) {
	dp[v][0]=0;
	for (int i:cptG[v]) {
		if (i==p) continue;
		if (isccl[i]) continue;
		dfs2(i,v,isccl);
		dp[v][0]+=max(dp[i][0],dp[i][1]);
	}
	dp[v][1]=-INF;
	for (int i:cptG[v]) {
		if (i==p) continue;
		if (isccl[i]) continue;
		dp[v][1]=max(dp[v][1],dp[v][0]-max(dp[i][0],dp[i][1])+dp[i][0]+1);
	}
}
 
int main() {
	speed;
	cin>>n;
	vector<string> dct;
	for (int i=0;i<n;i++) {
		string a,b;
		cin>>a>>b;
		eg.emplace_back(a,b);
		dct.push_back(a);
		dct.push_back(b);
	}
	sort(all(dct));
	dct.resize(unique(all(dct))-dct.begin());
//	for (string s:dct) cout<<s<<"\n";
//	cout<<"name\n";
	fill(G,G+n,n);
	for (int i=0;i<n;i++) {
		auto [a,b]=eg[i];
		int va=lower_bound(all(dct),a)-dct.begin();
		int vb=lower_bound(all(dct),b)-dct.begin();
		G[va]=vb;
//		cout<<va<<" "<<vb<<" vab\n";
//		cout<<va<<" "<<G[G[va]]<<" G\n";
		cptG[va].push_back(vb);
		if (va!=vb) cptG[vb].push_back(va);
	}
//	for (int i=0;i<n;i++) {
//		cout<<i<<" : ";
//		for (int j:cptG[i]) cout<<j<<" ";
//		cout<<"\n";
//	}
	if (n&1) {
		cout<<"-1\n";
		return 0;
	}
	vector<bool> vis(n,0),tmpvis(n,0);
	vector<bool> isccl(n,0);
	int ttl=0;
	for (int i=0;i<n;i++) {
		if (vis[i]) continue;
		vector<int> ccl;
		int stt=-2;
		dfs(i,-1,vis,tmpvis,ccl,stt);
		dfsvis(i,vis);
//		cout<<i<<" i\n"<<flush;
//		for (int j:ccl) cout<<j<<" ";
//		cout<<" ccl\n"<<flush;
		for (int j:ccl) isccl[j]=true;
		for (int j:ccl) {
//			cout<<j<<" rt\n"<<flush;
			dfs2(j,-1,isccl);
		}
		if (ccl.size()==2) {
			int ans=dp[ccl[0]][0]+dp[ccl[1]][0]+2;
			ans=max(ans,max(dp[ccl[0]][0],dp[ccl[0]][1])+max(dp[ccl[1]][0],dp[ccl[1]][1]));
			ttl+=ans;
			continue;
		}
		vector<vector<int> > cdp(ccl.size(),vector<int>(2,0));
		cdp[0][0]=dp[ccl[0]][0];
		cdp[0][1]=dp[ccl[0]][1];
		for (i=1;i<ccl.size();i++) {
			cdp[i][0]=max(cdp[i-1][0],cdp[i-1][1])+dp[ccl[i]][0];
			cdp[i][1]=max(max(cdp[i-1][0],cdp[i-1][1])+dp[ccl[i]][1],cdp[i-1][0]+dp[ccl[i]][0]+1);
		}
		int ans=max(cdp[ccl.size()-1][0],cdp[ccl.size()-1][1]);
		int tmp=ccl[0];
		for (int j=0;j<ccl.size()-1;j++) ccl[j]=ccl[j+1];
		ccl[ccl.size()-1]=tmp;
//		for (int j:ccl) cout<<j<<" ";
//		cout<<" ccl\n"<<flush;
		fill(all(cdp),vector<int>(2,0));
		cdp[0][0]=dp[ccl[0]][0];
		cdp[0][1]=dp[ccl[0]][1];
		for (i=1;i<ccl.size();i++) {
			cdp[i][0]=max(cdp[i-1][0],cdp[i-1][1])+dp[ccl[i]][0];
			cdp[i][1]=max(max(cdp[i-1][0],cdp[i-1][1])+dp[ccl[i]][1],cdp[i-1][0]+dp[ccl[i]][0]+1);
		}
		ans=max(ans,max(cdp[ccl.size()-1][0],cdp[ccl.size()-1][1]));
		ttl+=ans;
	}
	cout<<n-ttl<<"\n";
	return 0;
}

/*
4
a f
d f
g f
f f
*/

Compilation message

polygon.cpp: In function 'int main()':
polygon.cpp:143:13: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  143 |   for (i=1;i<ccl.size();i++) {
      |            ~^~~~~~~~~~~
polygon.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 j=0;j<ccl.size()-1;j++) ccl[j]=ccl[j+1];
      |                ~^~~~~~~~~~~~~
polygon.cpp:156:13: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  156 |   for (i=1;i<ccl.size();i++) {
      |            ~^~~~~~~~~~~

Subtask #1
21.0 / 21.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 3420 KB Output is correct
2 Correct 1 ms 3420 KB Output is correct
3 Correct 1 ms 3420 KB Output is correct
4 Correct 2 ms 3420 KB Output is correct
5 Correct 1 ms 3420 KB Output is correct
6 Correct 1 ms 3420 KB Output is correct
7 Correct 1 ms 3420 KB Output is correct
8 Correct 1 ms 3420 KB Output is correct
9 Correct 1 ms 3420 KB Output is correct
10 Correct 1 ms 3420 KB Output is correct
11 Correct 1 ms 3420 KB Output is correct
12 Correct 1 ms 3420 KB Output is correct
13 Correct 1 ms 3420 KB Output is correct
14 Correct 1 ms 3420 KB Output is correct
15 Correct 1 ms 3420 KB Output is correct

Subtask #2
25.0 / 25.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 3416 KB Output is correct
2 Correct 1 ms 3416 KB Output is correct
3 Correct 1 ms 3420 KB Output is correct
4 Correct 164 ms 35980 KB Output is correct
5 Correct 425 ms 22656 KB Output is correct
6 Correct 141 ms 35804 KB Output is correct
7 Correct 142 ms 20884 KB Output is correct

Subtask #3
0 / 29.0

# Verdict Execution time Memory Grader output
1 Correct 147 ms 22724 KB Output is correct
2 Correct 148 ms 24892 KB Output is correct
3 Execution timed out 2025 ms 22276 KB Time limit exceeded
4 Halted 0 ms 0 KB -

Subtask #4
0 / 25.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 3420 KB Output is correct
2 Correct 1 ms 3420 KB Output is correct
3 Correct 1 ms 3420 KB Output is correct
4 Correct 2 ms 3420 KB Output is correct
5 Correct 1 ms 3420 KB Output is correct
6 Correct 1 ms 3420 KB Output is correct
7 Correct 1 ms 3420 KB Output is correct
8 Correct 1 ms 3420 KB Output is correct
9 Correct 1 ms 3420 KB Output is correct
10 Correct 1 ms 3420 KB Output is correct
11 Correct 1 ms 3420 KB Output is correct
12 Correct 1 ms 3420 KB Output is correct
13 Correct 1 ms 3420 KB Output is correct
14 Correct 1 ms 3420 KB Output is correct
15 Correct 1 ms 3420 KB Output is correct
16 Correct 3 ms 3416 KB Output is correct
17 Correct 1 ms 3416 KB Output is correct
18 Correct 1 ms 3420 KB Output is correct
19 Correct 164 ms 35980 KB Output is correct
20 Correct 425 ms 22656 KB Output is correct
21 Correct 141 ms 35804 KB Output is correct
22 Correct 142 ms 20884 KB Output is correct
23 Correct 147 ms 22724 KB Output is correct
24 Correct 148 ms 24892 KB Output is correct
25 Execution timed out 2025 ms 22276 KB Time limit exceeded
26 Halted 0 ms 0 KB -