oj.uz

Submission #1108536

# Submission time Handle Problem Language Result Execution time Memory
1108536 2024-11-04T11:20:55 Z _rain_ Love Polygon (BOI18_polygon) C++14
75 / 100
 119 ms 35080 KB 
#include<bits/stdc++.h>
using namespace std;
 
typedef long long ll;
#define name "main"
 
const int N=(int)1e5;
vector<string>nen;
string s1[N+2],s2[N+2];
int deg[N+2],num[N+2],low[N+2],id[N+2],scc=0,timedfs=0;
int u[N+2],v[N+2],to[N+2],dp[N+2][2],n;
vector<int>ord,bag[N+2],ke[N+2];
bool used[N+2],del[N+2];
 
void buildup(int u){
	num[u]=low[u]=++timedfs;
	ord.push_back(u);
	
	if (!num[to[u]]&&!del[to[u]]){
		buildup(to[u]);
		low[u]=min(low[u],low[to[u]]);
	}
	else if (!del[to[u]]) low[u]=min(low[u],num[to[u]]);
	if (low[u]==num[u]){
		int v;
		++scc;
		do{
			v=ord.back();
			ord.pop_back();
			id[v]=scc;
			del[v]=true;
			bag[id[v]].push_back(v);
		}while(v!=u);
	}
}
void dfs(int u){
	if (ke[u].size()==0){
		dp[u][0]=0;
		dp[u][1]=1;
		return;
	}
	for(auto&v:ke[u]){
		dfs(v);
		dp[u][1]+=dp[v][0];
	}
	dp[u][1]++;
	for(auto&v:ke[u]){
		dp[u][0]=max(dp[u][0],dp[u][1]-1+max(0,dp[v][1]-dp[v][0]));
	}
}
 
int32_t main(){
	ios::sync_with_stdio(0);
	cin.tie(0); cout.tie(0);
	
	cin>>n;
	if (n%2==1){
		cout<<-1;
		exit(0);
	}
	for(int i=1;i<=n;++i){
		cin>>s1[i]>>s2[i];
		nen.push_back(s1[i]);
		nen.push_back(s2[i]);
	}
	sort(nen.begin(),nen.end());
	nen.resize(unique(nen.begin(),nen.end())-nen.begin());
	for(int i=1;i<=n;++i){
		u[i]=upper_bound(nen.begin(),nen.end(),s1[i])-nen.begin();
		v[i]=upper_bound(nen.begin(),nen.end(),s2[i])-nen.begin();
		to[u[i]]=v[i];
	}
	assert(nen.size()==n);
	for(int i=1;i<=n;++i) if (!num[i]) buildup(i);
	for(int i=1;i<=scc;++i){
		for(auto&u:bag[i]){
			if (id[to[u]]!=i){
				ke[id[to[u]]].push_back(i);
				deg[i]++;
			}
		}
	}
	for(int i=1;i<=scc;++i) {
		sort(ke[i].begin(),ke[i].end());
		ke[i].resize(unique(ke[i].begin(),ke[i].end())-ke[i].begin());
	}
	int ans=0;
	// for(int i=1;i<=n;++i){
	// 	cout<<u[i]<<' '<<v[i]<<'\n';
	// }
	// for(int i=1;i<=n;++i) cout<<id[i]<<' '; cout<<'\n';
	for(int i=1;i<=scc;++i){
		if (deg[i]==0){
			dfs(i);
			if (bag[i].size()==2) ans+=2; else ans+=bag[i].size()/2;
			if (bag[i].size()%2==0) ans+=dp[i][1]-1; else ans+=dp[i][0];
		}
	}
	cout<<n-ans;
	exit(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 polygon.cpp:1:
polygon.cpp: In function 'int32_t main()':
polygon.cpp:73:19: warning: comparison of integer expressions of different signedness: 'std::vector<std::__cxx11::basic_string<char> >::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   73 |  assert(nen.size()==n);
      |         ~~~~~~~~~~^~~

Subtask #1
21.0 / 21.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 14928 KB Output is correct
2 Correct 4 ms 14928 KB Output is correct
3 Correct 3 ms 14928 KB Output is correct
4 Correct 3 ms 15096 KB Output is correct
5 Correct 3 ms 13048 KB Output is correct
6 Correct 3 ms 12720 KB Output is correct
7 Correct 3 ms 14928 KB Output is correct
8 Correct 3 ms 14928 KB Output is correct
9 Correct 3 ms 14928 KB Output is correct
10 Correct 4 ms 14928 KB Output is correct
11 Correct 3 ms 14928 KB Output is correct
12 Correct 3 ms 14928 KB Output is correct
13 Correct 3 ms 14928 KB Output is correct
14 Correct 3 ms 14928 KB Output is correct
15 Correct 3 ms 14928 KB Output is correct

Subtask #2
25.0 / 25.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 14928 KB Output is correct
2 Correct 3 ms 14928 KB Output is correct
3 Correct 3 ms 14928 KB Output is correct
4 Correct 115 ms 31152 KB Output is correct
5 Correct 107 ms 23984 KB Output is correct
6 Correct 105 ms 32176 KB Output is correct
7 Correct 3 ms 12880 KB Output is correct

Subtask #3
29.0 / 29.0

# Verdict Execution time Memory Grader output
1 Correct 117 ms 28684 KB Output is correct
2 Correct 116 ms 30384 KB Output is correct
3 Correct 90 ms 26288 KB Output is correct
4 Correct 2 ms 12880 KB Output is correct
5 Correct 119 ms 35080 KB Output is correct
6 Correct 111 ms 27912 KB Output is correct
7 Correct 111 ms 27912 KB Output is correct
8 Correct 103 ms 27572 KB Output is correct
9 Correct 105 ms 27340 KB Output is correct
10 Correct 77 ms 27056 KB Output is correct
11 Correct 2 ms 14928 KB Output is correct
12 Correct 2 ms 14928 KB Output is correct
13 Correct 3 ms 14928 KB Output is correct
14 Correct 3 ms 14928 KB Output is correct

Subtask #4
0 / 25.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 14928 KB Output is correct
2 Correct 4 ms 14928 KB Output is correct
3 Correct 3 ms 14928 KB Output is correct
4 Correct 3 ms 15096 KB Output is correct
5 Correct 3 ms 13048 KB Output is correct
6 Correct 3 ms 12720 KB Output is correct
7 Correct 3 ms 14928 KB Output is correct
8 Correct 3 ms 14928 KB Output is correct
9 Correct 3 ms 14928 KB Output is correct
10 Correct 4 ms 14928 KB Output is correct
11 Correct 3 ms 14928 KB Output is correct
12 Correct 3 ms 14928 KB Output is correct
13 Correct 3 ms 14928 KB Output is correct
14 Correct 3 ms 14928 KB Output is correct
15 Correct 3 ms 14928 KB Output is correct
16 Correct 3 ms 14928 KB Output is correct
17 Correct 3 ms 14928 KB Output is correct
18 Correct 3 ms 14928 KB Output is correct
19 Correct 115 ms 31152 KB Output is correct
20 Correct 107 ms 23984 KB Output is correct
21 Correct 105 ms 32176 KB Output is correct
22 Correct 3 ms 12880 KB Output is correct
23 Correct 117 ms 28684 KB Output is correct
24 Correct 116 ms 30384 KB Output is correct
25 Correct 90 ms 26288 KB Output is correct
26 Correct 2 ms 12880 KB Output is correct
27 Correct 119 ms 35080 KB Output is correct
28 Correct 111 ms 27912 KB Output is correct
29 Correct 111 ms 27912 KB Output is correct
30 Correct 103 ms 27572 KB Output is correct
31 Correct 105 ms 27340 KB Output is correct
32 Correct 77 ms 27056 KB Output is correct
33 Correct 2 ms 14928 KB Output is correct
34 Correct 2 ms 14928 KB Output is correct
35 Correct 3 ms 14928 KB Output is correct
36 Correct 3 ms 14928 KB Output is correct
37 Incorrect 115 ms 28944 KB Output isn't correct
38 Halted 0 ms 0 KB -