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Submission #1108540

# Submission time Handle Problem Language Result Execution time Memory
1108540 2024-11-04T11:27:50 Z _rain_ Love Polygon (BOI18_polygon) C++14
75 / 100
 145 ms 147652 KB 
#include<bits/stdc++.h>
using namespace std;
 
typedef long long ll;
#define name "main"
 
const int N=(int)1e6;
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 21 ms 124496 KB Output is correct
2 Correct 20 ms 124496 KB Output is correct
3 Correct 21 ms 124348 KB Output is correct
4 Correct 21 ms 124496 KB Output is correct
5 Correct 22 ms 114000 KB Output is correct
6 Correct 19 ms 114060 KB Output is correct
7 Correct 22 ms 122448 KB Output is correct
8 Correct 21 ms 124496 KB Output is correct
9 Correct 22 ms 124496 KB Output is correct
10 Correct 21 ms 124512 KB Output is correct
11 Correct 21 ms 124496 KB Output is correct
12 Correct 20 ms 124496 KB Output is correct
13 Correct 21 ms 124496 KB Output is correct
14 Correct 21 ms 124496 KB Output is correct
15 Correct 21 ms 124496 KB Output is correct

Subtask #2
25.0 / 25.0

# Verdict Execution time Memory Grader output
1 Correct 22 ms 122448 KB Output is correct
2 Correct 21 ms 122336 KB Output is correct
3 Correct 22 ms 122448 KB Output is correct
4 Correct 132 ms 139452 KB Output is correct
5 Correct 117 ms 132308 KB Output is correct
6 Correct 129 ms 140488 KB Output is correct
7 Correct 19 ms 114012 KB Output is correct

Subtask #3
29.0 / 29.0

# Verdict Execution time Memory Grader output
1 Correct 138 ms 140976 KB Output is correct
2 Correct 133 ms 142772 KB Output is correct
3 Correct 107 ms 136628 KB Output is correct
4 Correct 18 ms 114000 KB Output is correct
5 Correct 145 ms 147652 KB Output is correct
6 Correct 131 ms 140224 KB Output is correct
7 Correct 130 ms 140208 KB Output is correct
8 Correct 127 ms 139696 KB Output is correct
9 Correct 123 ms 139700 KB Output is correct
10 Correct 110 ms 139464 KB Output is correct
11 Correct 22 ms 124508 KB Output is correct
12 Correct 19 ms 124496 KB Output is correct
13 Correct 22 ms 124344 KB Output is correct
14 Correct 22 ms 124496 KB Output is correct

Subtask #4
0 / 25.0

# Verdict Execution time Memory Grader output
1 Correct 21 ms 124496 KB Output is correct
2 Correct 20 ms 124496 KB Output is correct
3 Correct 21 ms 124348 KB Output is correct
4 Correct 21 ms 124496 KB Output is correct
5 Correct 22 ms 114000 KB Output is correct
6 Correct 19 ms 114060 KB Output is correct
7 Correct 22 ms 122448 KB Output is correct
8 Correct 21 ms 124496 KB Output is correct
9 Correct 22 ms 124496 KB Output is correct
10 Correct 21 ms 124512 KB Output is correct
11 Correct 21 ms 124496 KB Output is correct
12 Correct 20 ms 124496 KB Output is correct
13 Correct 21 ms 124496 KB Output is correct
14 Correct 21 ms 124496 KB Output is correct
15 Correct 21 ms 124496 KB Output is correct
16 Correct 22 ms 122448 KB Output is correct
17 Correct 21 ms 122336 KB Output is correct
18 Correct 22 ms 122448 KB Output is correct
19 Correct 132 ms 139452 KB Output is correct
20 Correct 117 ms 132308 KB Output is correct
21 Correct 129 ms 140488 KB Output is correct
22 Correct 19 ms 114012 KB Output is correct
23 Correct 138 ms 140976 KB Output is correct
24 Correct 133 ms 142772 KB Output is correct
25 Correct 107 ms 136628 KB Output is correct
26 Correct 18 ms 114000 KB Output is correct
27 Correct 145 ms 147652 KB Output is correct
28 Correct 131 ms 140224 KB Output is correct
29 Correct 130 ms 140208 KB Output is correct
30 Correct 127 ms 139696 KB Output is correct
31 Correct 123 ms 139700 KB Output is correct
32 Correct 110 ms 139464 KB Output is correct
33 Correct 22 ms 124508 KB Output is correct
34 Correct 19 ms 124496 KB Output is correct
35 Correct 22 ms 124344 KB Output is correct
36 Correct 22 ms 124496 KB Output is correct
37 Incorrect 143 ms 141512 KB Output isn't correct
38 Halted 0 ms 0 KB -