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Submission #350036

# Submission time Handle Problem Language Result Execution time Memory
350036 2021-01-18T23:20:52 Z arnold518 Matching (COCI20_matching) C++14
58 / 110
 1008 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 = 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<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 194 ms 286956 KB Output is correct
2 Correct 194 ms 286956 KB Output is correct

Subtask #2
6.0 / 6.0

# Verdict Execution time Memory Grader output
1 Correct 194 ms 286956 KB Output is correct
2 Correct 194 ms 286956 KB Output is correct
3 Correct 197 ms 287004 KB Output is correct
4 Correct 194 ms 286956 KB Output is correct
5 Correct 194 ms 286956 KB Output is correct
6 Correct 194 ms 286956 KB Output is correct
7 Correct 195 ms 286956 KB Output is correct

Subtask #3
7.0 / 7.0

# Verdict Execution time Memory Grader output
1 Correct 194 ms 286956 KB Output is correct
2 Correct 194 ms 286956 KB Output is correct
3 Correct 197 ms 287004 KB Output is correct
4 Correct 194 ms 286956 KB Output is correct
5 Correct 194 ms 286956 KB Output is correct
6 Correct 194 ms 286956 KB Output is correct
7 Correct 195 ms 286956 KB Output is correct
8 Correct 195 ms 287084 KB Output is correct
9 Correct 193 ms 286956 KB Output is correct
10 Correct 195 ms 287084 KB Output is correct
11 Correct 195 ms 287084 KB Output is correct
12 Correct 193 ms 286956 KB Output is correct

Subtask #4
40.0 / 40.0

# Verdict Execution time Memory Grader output
1 Correct 194 ms 286956 KB Output is correct
2 Correct 194 ms 286956 KB Output is correct
3 Correct 197 ms 287004 KB Output is correct
4 Correct 194 ms 286956 KB Output is correct
5 Correct 194 ms 286956 KB Output is correct
6 Correct 194 ms 286956 KB Output is correct
7 Correct 195 ms 286956 KB Output is correct
8 Correct 195 ms 287084 KB Output is correct
9 Correct 193 ms 286956 KB Output is correct
10 Correct 195 ms 287084 KB Output is correct
11 Correct 195 ms 287084 KB Output is correct
12 Correct 193 ms 286956 KB Output is correct
13 Correct 218 ms 292960 KB Output is correct
14 Correct 219 ms 292848 KB Output is correct
15 Correct 219 ms 292972 KB Output is correct
16 Correct 219 ms 292844 KB Output is correct
17 Correct 219 ms 292836 KB Output is correct
18 Correct 220 ms 292840 KB Output is correct
19 Correct 223 ms 292840 KB Output is correct
20 Correct 221 ms 292840 KB Output is correct
21 Correct 221 ms 292988 KB Output is correct
22 Correct 218 ms 293092 KB Output is correct
23 Correct 221 ms 292972 KB Output is correct
24 Correct 220 ms 292976 KB Output is correct

Subtask #5
0 / 52.0

# Verdict Execution time Memory Grader output
1 Correct 194 ms 286956 KB Output is correct
2 Correct 194 ms 286956 KB Output is correct
3 Correct 197 ms 287004 KB Output is correct
4 Correct 194 ms 286956 KB Output is correct
5 Correct 194 ms 286956 KB Output is correct
6 Correct 194 ms 286956 KB Output is correct
7 Correct 195 ms 286956 KB Output is correct
8 Correct 195 ms 287084 KB Output is correct
9 Correct 193 ms 286956 KB Output is correct
10 Correct 195 ms 287084 KB Output is correct
11 Correct 195 ms 287084 KB Output is correct
12 Correct 193 ms 286956 KB Output is correct
13 Correct 218 ms 292960 KB Output is correct
14 Correct 219 ms 292848 KB Output is correct
15 Correct 219 ms 292972 KB Output is correct
16 Correct 219 ms 292844 KB Output is correct
17 Correct 219 ms 292836 KB Output is correct
18 Correct 220 ms 292840 KB Output is correct
19 Correct 223 ms 292840 KB Output is correct
20 Correct 221 ms 292840 KB Output is correct
21 Correct 221 ms 292988 KB Output is correct
22 Correct 218 ms 293092 KB Output is correct
23 Correct 221 ms 292972 KB Output is correct
24 Correct 220 ms 292976 KB Output is correct
25 Runtime error 1008 ms 524292 KB Execution killed with signal 9 (could be triggered by violating memory limits)
26 Halted 0 ms 0 KB -