oj.uz

Submission #350039

# Submission time Handle Problem Language Result Execution time Memory
350039 2021-01-18T23:28:29 Z arnold518 Matching (COCI20_matching) C++14
58 / 110
 1520 ms 287796 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 = 5e6;

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[MAXN+10], ridx[MAXN+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 5120 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 5120 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 5120 KB Output is correct
6 Correct 4 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 5120 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 5120 KB Output is correct
6 Correct 4 ms 5100 KB Output is correct
7 Correct 4 ms 5100 KB Output is correct
8 Correct 5 ms 5120 KB Output is correct
9 Correct 4 ms 5100 KB Output is correct
10 Correct 4 ms 5100 KB Output is correct
11 Correct 5 ms 5100 KB Output is correct
12 Correct 5 ms 5120 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 5120 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 5120 KB Output is correct
6 Correct 4 ms 5100 KB Output is correct
7 Correct 4 ms 5100 KB Output is correct
8 Correct 5 ms 5120 KB Output is correct
9 Correct 4 ms 5100 KB Output is correct
10 Correct 4 ms 5100 KB Output is correct
11 Correct 5 ms 5100 KB Output is correct
12 Correct 5 ms 5120 KB Output is correct
13 Correct 27 ms 9148 KB Output is correct
14 Correct 27 ms 9148 KB Output is correct
15 Correct 27 ms 9152 KB Output is correct
16 Correct 27 ms 9152 KB Output is correct
17 Correct 26 ms 9152 KB Output is correct
18 Correct 27 ms 9148 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 29 ms 9556 KB Output is correct

Subtask #5
0 / 52.0

# Verdict Execution time Memory Grader output
1 Correct 4 ms 5100 KB Output is correct
2 Correct 4 ms 5120 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 5120 KB Output is correct
6 Correct 4 ms 5100 KB Output is correct
7 Correct 4 ms 5100 KB Output is correct
8 Correct 5 ms 5120 KB Output is correct
9 Correct 4 ms 5100 KB Output is correct
10 Correct 4 ms 5100 KB Output is correct
11 Correct 5 ms 5100 KB Output is correct
12 Correct 5 ms 5120 KB Output is correct
13 Correct 27 ms 9148 KB Output is correct
14 Correct 27 ms 9148 KB Output is correct
15 Correct 27 ms 9152 KB Output is correct
16 Correct 27 ms 9152 KB Output is correct
17 Correct 26 ms 9152 KB Output is correct
18 Correct 27 ms 9148 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 29 ms 9556 KB Output is correct
25 Runtime error 1520 ms 287796 KB Execution killed with signal 11 (could be triggered by violating memory limits)
26 Halted 0 ms 0 KB -