oj.uz

Submission #949966

# Submission time Handle Problem Language Result Execution time Memory
949966 2024-03-20T01:42:27 Z koukirocks Love Polygon (BOI18_polygon) C++17
46 / 100
 2000 ms 37336 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 v,vector<bool>& vis) {
	vis[v]=true;
	queue<int> BFS;
	BFS.push(v);
	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 3416 KB Output is correct
8 Correct 2 ms 3416 KB Output is correct
9 Correct 1 ms 3416 KB Output is correct
10 Correct 1 ms 3416 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 2 ms 3244 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 1 ms 3416 KB Output is correct
2 Correct 1 ms 3420 KB Output is correct
3 Correct 1 ms 3420 KB Output is correct
4 Correct 153 ms 35160 KB Output is correct
5 Correct 451 ms 19932 KB Output is correct
6 Correct 143 ms 37336 KB Output is correct
7 Correct 114 ms 19520 KB Output is correct

Subtask #3
0 / 29.0

# Verdict Execution time Memory Grader output
1 Correct 131 ms 21136 KB Output is correct
2 Correct 131 ms 21552 KB Output is correct
3 Execution timed out 2076 ms 21188 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 3416 KB Output is correct
8 Correct 2 ms 3416 KB Output is correct
9 Correct 1 ms 3416 KB Output is correct
10 Correct 1 ms 3416 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 2 ms 3244 KB Output is correct
15 Correct 1 ms 3420 KB Output is correct
16 Correct 1 ms 3416 KB Output is correct
17 Correct 1 ms 3420 KB Output is correct
18 Correct 1 ms 3420 KB Output is correct
19 Correct 153 ms 35160 KB Output is correct
20 Correct 451 ms 19932 KB Output is correct
21 Correct 143 ms 37336 KB Output is correct
22 Correct 114 ms 19520 KB Output is correct
23 Correct 131 ms 21136 KB Output is correct
24 Correct 131 ms 21552 KB Output is correct
25 Execution timed out 2076 ms 21188 KB Time limit exceeded
26 Halted 0 ms 0 KB -