oj.uz

Submission #350040

# Submission time Handle Problem Language Result Execution time Memory
350040 2021-01-18T23:29:09 Z arnold518 Matching (COCI20_matching) C++14
110 / 110
 2393 ms 231208 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 = 1e5;
const int MAXM = 6e6;

int N, M, M1, M2;
pii A[MAXN+10];
vector<int> X[MAXN+10], Y[MAXN+10];
int P[MAXN+10], Q[MAXN+10];
pii E[MAXN*2+10];

vector<pii> adj, radj;
int idx[MAXM+10], ridx[MAXM+10];

bool vis[MAXM+10];
vector<int> S;
void dfs(int now)
{
	vis[now]=true;
	for(int i=idx[now]; i<idx[now+1]; i++)
	{
		int nxt=adj[i].second;
		if(vis[nxt]) continue;
		dfs(nxt);
	}
	S.push_back(now);
}

int scc[MAXM+10], scnt;
void dfs2(int now)
{
	scc[now]=scnt;
	for(int i=ridx[now]; i<ridx[now+1]; i++)
	{
		int nxt=radj[i].second;
		if(scc[nxt]) continue;
		dfs2(nxt);
	}
}

void addEdge(int u, int v)
{
	if(u==0 || v==0) return;
	//printf("%d %d\n", u, v);
	adj.push_back({u, v});
	radj.push_back({v, u});
	//adj[u].push_back(v);
	//radj[v].push_back(u);
}

pii nodes[MAXM+10];

int update(int node, int tl, int tr, int p, int k)
{
	if(p<tl || tr<p) return node;
	int ret=++M;
	if(tl==tr)
	{
		addEdge(ret, k);
		return ret;
	}
	int mid=tl+tr>>1;
	nodes[ret]={update(nodes[node].first, tl, mid, p, k), update(nodes[node].second, mid+1, tr, p, k)};
	addEdge(ret, nodes[ret].first);
	addEdge(ret, nodes[ret].second);
	return ret;
}

void query(int node, int tl, int tr, int l, int r, int k)
{
	if(node==0) return;
	if(r<tl || tr<l) return;
	if(l<=tl && tr<=r)
	{
		addEdge(k, node);
		return;
	}
	int mid=tl+tr>>1;
	query(nodes[node].first, tl, mid, l, r, k);
	query(nodes[node].second, mid+1, tr, l, r, k);
}

int main()
{
	scanf("%d", &N);
	for(int i=1; i<=N; i++)
	{
		scanf("%d%d", &A[i].first, &A[i].second);
		X[A[i].first].push_back(i);
		Y[A[i].second].push_back(i);
	}

	for(int i=1; i<=MAXN; i++)
	{
		if(X[i].size()==2)
		{
			M++;
			if(A[X[i][0]]>A[X[i][1]]) swap(X[i][0], X[i][1]);
			E[M]={X[i][0], X[i][1]};
			P[X[i][0]]=M;
			P[X[i][1]]=M;
		}
	}
	M1=M;
	for(int i=1; i<=MAXN; i++)
	{
		if(Y[i].size()==2)
		{
			M++;
			if(A[Y[i][0]]>A[Y[i][1]]) swap(Y[i][0], Y[i][1]);
			E[M]={Y[i][0], Y[i][1]};
			Q[Y[i][0]]=M;
			Q[Y[i][1]]=M;
		}
	}
	M2=M;

	for(int i=1; i<=N; i++)
	{
		if(P[i]==0 && Q[i]==0) 
		{
			return !printf("NE\n");
		}
		if(P[i] && Q[i])
		{
			addEdge(P[i]+M2, Q[i]);
			addEdge(P[i], Q[i]+M2);
			addEdge(Q[i]+M2, P[i]);
			addEdge(Q[i], P[i]+M2);
		}
		else if(P[i])
		{
			addEdge(P[i]+M2, P[i]);
		}
		else if(Q[i])
		{
			addEdge(Q[i]+M2, Q[i]);
		}
	}
	M*=2;

/*
	for(int i=1; i<=M1; i++) for(int j=M1+1; j<=M2; j++)
	{
		if(A[E[i].first].second<=A[E[j].first].second && A[E[j].second].second<=A[E[i].second].second)
		{
			if(A[E[j].first].first<=A[E[i].first].first && A[E[i].second].first<=A[E[j].second].first)
			{
				addEdge(i, j+M2);
				addEdge(j, i+M2);
			}	
		}
	}
*/

	vector<pii> V;
	for(int i=1; i<=M1; i++)
	{
		V.push_back({A[E[i].first].second, i});
		V.push_back({A[E[i].second].second+1, -i});
	}

	for(int i=M1+1; i<=M2; i++)
	{
		V.push_back({A[E[i].first].second, i});
	}
	sort(V.begin(), V.end());

	int root=++M;
	for(auto it : V)
	{
		if(it.second>=M1+1)
		{
			query(root, 1, MAXN, A[E[it.second].first].first, A[E[it.second].second].first, it.second);
		}
		else
		{
			if(it.second>=0)
			{
				root=update(root, 1, MAXN, A[E[it.second].first].first, it.second+M2);
			}
			else
			{
				root=update(root, 1, MAXN, A[E[-it.second].first].first, 0);	
			}
		}
	}

	V.clear();
	for(int i=M1+1; i<=M2; i++)
	{
		V.push_back({A[E[i].first].first, i});
		V.push_back({A[E[i].second].first+1, -i});
	}

	for(int i=1; i<=M1; i++)
	{
		V.push_back({A[E[i].first].first, i+M2});
	}
	sort(V.begin(), V.end());

	root=++M;
	for(auto it : V)
	{
		if(it.second>=M2+1)
		{
			query(root, 1, MAXN, A[E[it.second-M2].first].second, A[E[it.second-M2].second].second, it.second-M2);
		}
		else
		{
			if(it.second>=0)
			{
				root=update(root, 1, MAXN, A[E[it.second].first].second, it.second+M2);
			}
			else
			{
				root=update(root, 1, MAXN, A[E[-it.second].first].second, 0);	
			}
		}
	}

	sort(adj.begin(), adj.end());
	sort(radj.begin(), radj.end());

	for(int i=0, j=1; i<adj.size(); i++)
	{
		for(; j<=adj[i].first; j++) idx[j]=i;
	}
	idx[M+1]=adj.size();

	for(int i=0, j=1; i<radj.size(); i++)
	{
		for(; j<=radj[i].first; j++) ridx[j]=i;
	}
	ridx[M+1]=radj.size();

	for(int i=1; i<=M; i++) if(!vis[i]) dfs(i);
	reverse(S.begin(), S.end());
	for(auto it : S)
	{
		if(scc[it]) continue;
		scnt++;
		dfs2(it);
	}

	for(int i=1; i<=M2; i++)
	{
		//printf("%d %d\n", E[i].first, E[i].second);
		//printf("%d %d\n", scc[i], scc[i+M2]);
		if(scc[i]==scc[i+M2])
		{
			return !printf("NE\n");
		}
	}

	printf("DA\n");
	vector<int> ans;
	for(int i=1; i<=M2; i++)
	{
		if(scc[i]>scc[i+M2])
		{
			printf("%d %d\n", E[i].first, E[i].second);
			ans.push_back(E[i].first);
			ans.push_back(E[i].second);
		}
	}

	assert(ans.size()==N);
	sort(ans.begin(), ans.end());
	ans.erase(unique(ans.begin(), ans.end()), ans.end());
	assert(ans.size()==N);
}

Compilation message

matching.cpp: In function 'int update(int, int, int, int, int)':
matching.cpp:67:12: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   67 |  int mid=tl+tr>>1;
      |          ~~^~~
matching.cpp: In function 'void query(int, int, int, int, int, int)':
matching.cpp:83:12: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   83 |  int mid=tl+tr>>1;
      |          ~~^~~
matching.cpp: In function 'int main()':
matching.cpp:230:21: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  230 |  for(int i=0, j=1; i<adj.size(); i++)
      |                    ~^~~~~~~~~~~
matching.cpp:236:21: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  236 |  for(int i=0, j=1; i<radj.size(); i++)
      |                    ~^~~~~~~~~~~~
In file included from /usr/include/c++/9/cassert:44,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:33,
                 from matching.cpp:1:
matching.cpp:273:19: warning: comparison of integer expressions of different signedness: 'std::vector<int>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
  273 |  assert(ans.size()==N);
      |         ~~~~~~~~~~^~~
matching.cpp:276:19: warning: comparison of integer expressions of different signedness: 'std::vector<int>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
  276 |  assert(ans.size()==N);
      |         ~~~~~~~~~~^~~
matching.cpp:90:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   90 |  scanf("%d", &N);
      |  ~~~~~^~~~~~~~~~
matching.cpp:93:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   93 |   scanf("%d%d", &A[i].first, &A[i].second);
      |   ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Subtask #1
5.0 / 5.0

# Verdict Execution time Memory Grader output
1 Correct 4 ms 5100 KB Output is correct
2 Correct 4 ms 5100 KB Output is correct

Subtask #2
6.0 / 6.0

# Verdict Execution time Memory Grader output
1 Correct 4 ms 5100 KB Output is correct
2 Correct 4 ms 5100 KB Output is correct
3 Correct 4 ms 5100 KB Output is correct
4 Correct 4 ms 5100 KB Output is correct
5 Correct 4 ms 5100 KB Output is correct
6 Correct 5 ms 5100 KB Output is correct
7 Correct 4 ms 5100 KB Output is correct

Subtask #3
7.0 / 7.0

# Verdict Execution time Memory Grader output
1 Correct 4 ms 5100 KB Output is correct
2 Correct 4 ms 5100 KB Output is correct
3 Correct 4 ms 5100 KB Output is correct
4 Correct 4 ms 5100 KB Output is correct
5 Correct 4 ms 5100 KB Output is correct
6 Correct 5 ms 5100 KB Output is correct
7 Correct 4 ms 5100 KB Output is correct
8 Correct 4 ms 5100 KB Output is correct
9 Correct 5 ms 5100 KB Output is correct
10 Correct 4 ms 5100 KB Output is correct
11 Correct 4 ms 5100 KB Output is correct
12 Correct 4 ms 5100 KB Output is correct

Subtask #4
40.0 / 40.0

# Verdict Execution time Memory Grader output
1 Correct 4 ms 5100 KB Output is correct
2 Correct 4 ms 5100 KB Output is correct
3 Correct 4 ms 5100 KB Output is correct
4 Correct 4 ms 5100 KB Output is correct
5 Correct 4 ms 5100 KB Output is correct
6 Correct 5 ms 5100 KB Output is correct
7 Correct 4 ms 5100 KB Output is correct
8 Correct 4 ms 5100 KB Output is correct
9 Correct 5 ms 5100 KB Output is correct
10 Correct 4 ms 5100 KB Output is correct
11 Correct 4 ms 5100 KB Output is correct
12 Correct 4 ms 5100 KB Output is correct
13 Correct 28 ms 9148 KB Output is correct
14 Correct 27 ms 9148 KB Output is correct
15 Correct 28 ms 9152 KB Output is correct
16 Correct 27 ms 9280 KB Output is correct
17 Correct 26 ms 9152 KB Output is correct
18 Correct 27 ms 9276 KB Output is correct
19 Correct 27 ms 9148 KB Output is correct
20 Correct 27 ms 9276 KB Output is correct
21 Correct 27 ms 9148 KB Output is correct
22 Correct 27 ms 9276 KB Output is correct
23 Correct 28 ms 9536 KB Output is correct
24 Correct 28 ms 9536 KB Output is correct

Subtask #5
52.0 / 52.0

# Verdict Execution time Memory Grader output
1 Correct 4 ms 5100 KB Output is correct
2 Correct 4 ms 5100 KB Output is correct
3 Correct 4 ms 5100 KB Output is correct
4 Correct 4 ms 5100 KB Output is correct
5 Correct 4 ms 5100 KB Output is correct
6 Correct 5 ms 5100 KB Output is correct
7 Correct 4 ms 5100 KB Output is correct
8 Correct 4 ms 5100 KB Output is correct
9 Correct 5 ms 5100 KB Output is correct
10 Correct 4 ms 5100 KB Output is correct
11 Correct 4 ms 5100 KB Output is correct
12 Correct 4 ms 5100 KB Output is correct
13 Correct 28 ms 9148 KB Output is correct
14 Correct 27 ms 9148 KB Output is correct
15 Correct 28 ms 9152 KB Output is correct
16 Correct 27 ms 9280 KB Output is correct
17 Correct 26 ms 9152 KB Output is correct
18 Correct 27 ms 9276 KB Output is correct
19 Correct 27 ms 9148 KB Output is correct
20 Correct 27 ms 9276 KB Output is correct
21 Correct 27 ms 9148 KB Output is correct
22 Correct 27 ms 9276 KB Output is correct
23 Correct 28 ms 9536 KB Output is correct
24 Correct 28 ms 9536 KB Output is correct
25 Correct 1597 ms 218676 KB Output is correct
26 Correct 1586 ms 220052 KB Output is correct
27 Correct 1572 ms 220084 KB Output is correct
28 Correct 1586 ms 220208 KB Output is correct
29 Correct 1578 ms 219700 KB Output is correct
30 Correct 1560 ms 219700 KB Output is correct
31 Correct 1563 ms 219700 KB Output is correct
32 Correct 1551 ms 219700 KB Output is correct
33 Correct 1432 ms 200804 KB Output is correct
34 Correct 1417 ms 199860 KB Output is correct
35 Correct 71 ms 14296 KB Output is correct
36 Correct 2393 ms 231208 KB Output is correct
37 Correct 1420 ms 202596 KB Output is correct
38 Correct 1419 ms 202472 KB Output is correct