#include <iostream>
#include <vector>
#include <algorithm>
using namespace std;
vector<int> p1(100001,-1);
vector<int> p2(100001,-1);
vector<vector<pair<int,int> > > v;
vector<int> lo;
vector<int> ind;
int edges=0;
int broj=1;
int dsu1(int x)
{
int px=x;
while(p1[x]!=-1)
x=p1[x];
int y=x;
while(px!=y)
{
int xx=p1[px];
p1[px]=y,px=xx;
}
return x;
}
int dsu2(int x)
{
int px=x;
while(p2[x]!=-1)
x=p2[x];
int y=x;
while(px!=y)
{
int xx=p2[px];
p2[px]=y,px=xx;
}
return x;
}
void bridges(int x,int prev,int broj)
{
lo[x]=broj;
ind[x]=broj;
for(int i=0;i<v[x].size();i++)
{
if(v[x][i].second==prev)
continue;
if(ind[v[x][i].first]==-1)
{
bridges(v[x][i].first,v[x][i].second,broj+1);
lo[x]=min(lo[x],lo[v[x][i].first]);
if(lo[v[x][i].first]>ind[x])
{
cout<<x+1<<" "<<v[x][i].first+1<<endl;
}
}
else
lo[x]=min(lo[x],ind[v[x][i].first]);
}
}
int main()
{
ios_base::sync_with_stdio(false);
cin.tie();
cout.tie();
int n,m;
cin>>n>>m;
vector<pair<int,int> > vec;
v.insert(v.begin(),n,vec);
for(int i=0;i<m;i++)
{
int a,b;
cin>>a>>b;
a--;
b--;
int x=dsu1(a);
int y=dsu1(b);
if(x!=y)
{
p1[x]=y;
v[a].push_back(make_pair(b,edges));
v[b].push_back(make_pair(a,edges));
edges++;
}
else
{
int x1=dsu2(a);
int y1=dsu2(b);
if(x1!=y1)
{
p2[x1]=y1;
v[a].push_back(make_pair(b,edges));
v[b].push_back(make_pair(a,edges));
edges++;
}
}
}
p1.clear();
p2.clear();
for(int i=0;i<n;i++)
{
lo.push_back(0);
ind.push_back(-1);
}
for(int i=0;i<n;i++)
{
if(ind[i]==-1)
{
bridges(i,-1,1);
}
}
return 0;
}
Compilation message
pipes.cpp: In function 'void bridges(int, int, int)':
pipes.cpp:42:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
for(int i=0;i<v[x].size();i++)
~^~~~~~~~~~~~
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
3 ms |
1152 KB |
Output is correct |
2 |
Correct |
3 ms |
1152 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
7 ms |
1792 KB |
Output is correct |
2 |
Correct |
6 ms |
1536 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
105 ms |
1632 KB |
Output is correct |
2 |
Correct |
103 ms |
1480 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
178 ms |
2532 KB |
Output is correct |
2 |
Correct |
205 ms |
2168 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
317 ms |
4584 KB |
Output is correct |
2 |
Correct |
275 ms |
4220 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
447 ms |
11116 KB |
Output is correct |
2 |
Correct |
432 ms |
8172 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
698 ms |
12464 KB |
Output is correct |
2 |
Correct |
674 ms |
9320 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
960 ms |
15352 KB |
Output is correct |
2 |
Correct |
835 ms |
11060 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
1074 ms |
15232 KB |
Output is correct |
2 |
Correct |
1031 ms |
11080 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
1350 ms |
14544 KB |
Output is correct |
2 |
Correct |
1198 ms |
11244 KB |
Output is correct |