#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);
| ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
4 ms |
5100 KB |
Output is correct |
2 |
Correct |
4 ms |
5100 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
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 |
# |
결과 |
실행 시간 |
메모리 |
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 |
# |
결과 |
실행 시간 |
메모리 |
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 |
# |
결과 |
실행 시간 |
메모리 |
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 |