oj.uz

Submission #350037

# Submission time Handle Problem Language Result Execution time Memory
350037 2021-01-18T23:21:38 Z arnold518 Matching (COCI20_matching) C++14
58 / 110
 1252 ms 524292 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<int> adj[MAXM+10], radj[MAXM+10];

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

int scc[MAXM+10], scnt;
void dfs2(int now)
{
	scc[now]=scnt;
	for(int nxt : radj[now])
	{
		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[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);	
			}
		}
	}

	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:62:12: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   62 |  int mid=tl+tr>>1;
      |          ~~^~~
matching.cpp: In function 'void query(int, int, int, int, int, int)':
matching.cpp:78:12: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   78 |  int mid=tl+tr>>1;
      |          ~~^~~
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: In function 'int main()':
matching.cpp:253:19: warning: comparison of integer expressions of different signedness: 'std::vector<int>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
  253 |  assert(ans.size()==N);
      |         ~~~~~~~~~~^~~
matching.cpp:256:19: warning: comparison of integer expressions of different signedness: 'std::vector<int>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
  256 |  assert(ans.size()==N);
      |         ~~~~~~~~~~^~~
matching.cpp:85:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   85 |  scanf("%d", &N);
      |  ~~~~~^~~~~~~~~~
matching.cpp:88:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   88 |   scanf("%d%d", &A[i].first, &A[i].second);
      |   ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Subtask #1
5.0 / 5.0

# Verdict Execution time Memory Grader output
1 Correct 162 ms 239980 KB Output is correct
2 Correct 161 ms 239980 KB Output is correct

Subtask #2
6.0 / 6.0

# Verdict Execution time Memory Grader output
1 Correct 162 ms 239980 KB Output is correct
2 Correct 161 ms 239980 KB Output is correct
3 Correct 163 ms 239980 KB Output is correct
4 Correct 167 ms 239980 KB Output is correct
5 Correct 161 ms 239908 KB Output is correct
6 Correct 164 ms 240108 KB Output is correct
7 Correct 163 ms 239980 KB Output is correct

Subtask #3
7.0 / 7.0

# Verdict Execution time Memory Grader output
1 Correct 162 ms 239980 KB Output is correct
2 Correct 161 ms 239980 KB Output is correct
3 Correct 163 ms 239980 KB Output is correct
4 Correct 167 ms 239980 KB Output is correct
5 Correct 161 ms 239908 KB Output is correct
6 Correct 164 ms 240108 KB Output is correct
7 Correct 163 ms 239980 KB Output is correct
8 Correct 163 ms 240132 KB Output is correct
9 Correct 162 ms 240108 KB Output is correct
10 Correct 162 ms 239980 KB Output is correct
11 Correct 162 ms 240108 KB Output is correct
12 Correct 161 ms 239980 KB Output is correct

Subtask #4
40.0 / 40.0

# Verdict Execution time Memory Grader output
1 Correct 162 ms 239980 KB Output is correct
2 Correct 161 ms 239980 KB Output is correct
3 Correct 163 ms 239980 KB Output is correct
4 Correct 167 ms 239980 KB Output is correct
5 Correct 161 ms 239908 KB Output is correct
6 Correct 164 ms 240108 KB Output is correct
7 Correct 163 ms 239980 KB Output is correct
8 Correct 163 ms 240132 KB Output is correct
9 Correct 162 ms 240108 KB Output is correct
10 Correct 162 ms 239980 KB Output is correct
11 Correct 162 ms 240108 KB Output is correct
12 Correct 161 ms 239980 KB Output is correct
13 Correct 193 ms 245868 KB Output is correct
14 Correct 194 ms 245868 KB Output is correct
15 Correct 187 ms 245744 KB Output is correct
16 Correct 186 ms 245864 KB Output is correct
17 Correct 189 ms 245988 KB Output is correct
18 Correct 187 ms 245864 KB Output is correct
19 Correct 186 ms 245868 KB Output is correct
20 Correct 188 ms 245988 KB Output is correct
21 Correct 186 ms 245864 KB Output is correct
22 Correct 187 ms 245864 KB Output is correct
23 Correct 188 ms 246056 KB Output is correct
24 Correct 188 ms 246252 KB Output is correct

Subtask #5
0 / 52.0

# Verdict Execution time Memory Grader output
1 Correct 162 ms 239980 KB Output is correct
2 Correct 161 ms 239980 KB Output is correct
3 Correct 163 ms 239980 KB Output is correct
4 Correct 167 ms 239980 KB Output is correct
5 Correct 161 ms 239908 KB Output is correct
6 Correct 164 ms 240108 KB Output is correct
7 Correct 163 ms 239980 KB Output is correct
8 Correct 163 ms 240132 KB Output is correct
9 Correct 162 ms 240108 KB Output is correct
10 Correct 162 ms 239980 KB Output is correct
11 Correct 162 ms 240108 KB Output is correct
12 Correct 161 ms 239980 KB Output is correct
13 Correct 193 ms 245868 KB Output is correct
14 Correct 194 ms 245868 KB Output is correct
15 Correct 187 ms 245744 KB Output is correct
16 Correct 186 ms 245864 KB Output is correct
17 Correct 189 ms 245988 KB Output is correct
18 Correct 187 ms 245864 KB Output is correct
19 Correct 186 ms 245868 KB Output is correct
20 Correct 188 ms 245988 KB Output is correct
21 Correct 186 ms 245864 KB Output is correct
22 Correct 187 ms 245864 KB Output is correct
23 Correct 188 ms 246056 KB Output is correct
24 Correct 188 ms 246252 KB Output is correct
25 Runtime error 1252 ms 524292 KB Execution killed with signal 9 (could be triggered by violating memory limits)
26 Halted 0 ms 0 KB -