#include <bits/stdc++.h>
using namespace std;
int n,m;
vector<int> v[100001];
void read()
{
cin>>n>>m;
for(int i=1;i<=m;i++)
{
int x,y;
cin>>x>>y;
v[x].push_back(y);
v[y].push_back(x);
}
}
int t,in[100001],low[100001],used[100001];
int art[100001];
void dfsart(int i,int p)
{
used[i]=1;
in[i]=t++;
low[i]=in[i];
int c=0;
for(int j=0;j<v[i].size();j++)
{
int nb=v[i][j];
if(nb==p)continue;
if(!used[nb])
{
c++;
dfsart(nb,i);
low[i]=min(low[i],low[nb]);
if(p!=-1&&in[i]<=low[nb])
art[i]=1;
}
else low[i]=min(low[i],in[nb]);
}
if(p==-1&&c>1)
art[i]=1;
}
int c[100001],num;
void part(int i)
{
c[i]=num;
for(int j=0;j<v[i].size();j++)
{
int nb=v[i][j];
if(c[nb]||art[nb])continue;
part(nb);
}
}
vector<int> g[100001];
bool cmp(int i,int j)
{
return c[i]<c[j];
}
void construct()
{
num=n;
for(int i=1;i<=n;i++)
{
if(!c[i]&&!art[i])
{
num++;
part(i);
}
//cout<<c[i]<<" ";
}
//cout<<endl;
for(int i=1;i<=n;i++)
{
if(c[i])
{
//cout<<i<<" 1 "<<c[i]<<endl;
g[i].push_back(c[i]);
g[c[i]].push_back(i);
}
else
{
sort(v[i].begin(),v[i].end(),cmp);
for(int j=0;j<v[i].size();j++)
{
int nb=v[i][j];
if(c[nb]&&(j==0||c[nb]!=c[v[i][j-1]]))
{
//cout<<i<<" 2 "<<c[nb]<<endl;
g[i].push_back(c[nb]);
g[c[nb]].push_back(i);
}
else if(!c[nb]&&nb>i)
{
num++;
//cout<<i<<" 3 "<<num<<endl;
g[i].push_back(num);
g[num].push_back(i);
//cout<<nb<<" 4 "<<num<<endl;
g[nb].push_back(num);
g[num].push_back(nb);
}
}
}
}
}
int sz[100001];
int ans;
int used1[100001];
void dfs(int i,int p)
{
used1[i]=1;
if(i<=n)sz[i]=1;
for(int j=0;j<g[i].size();j++)
{
int nb=g[i][j];
if(nb==p)continue;
dfs(nb,i);
sz[i]+=sz[nb];
}
//cout<<i<<" > "<<sz[i]<<endl;
if(!art[i])return;
for(int j=0;j<g[i].size();j++)
{
int nb=g[i][j];
if(nb==p)continue;
int avail=(sz[nb]+1)*sz[nb];
int outside=n-sz[nb]-1;
ans-=avail*outside;
}
int avail=(n-sz[i]+1)*(n-sz[i]);
int outside=sz[i]-1;
ans-=avail*outside;
}
int main()
{
ios_base::sync_with_stdio(false);
cin.tie(NULL);
cout.tie(NULL);
read();
for(int i=1;i<=n;i++)
{
if(!used[i])dfsart(i,-1);
}
construct();
ans=n*(n-1)*(n-2);
for(int i=1;i<=n;i++)
if(!used1[i])dfs(i,-1);
cout<<ans<<endl;
return 0;
}
Compilation message
count_triplets.cpp: In function 'void dfsart(int, int)':
count_triplets.cpp:29:18: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
29 | for(int j=0;j<v[i].size();j++)
| ~^~~~~~~~~~~~
count_triplets.cpp: In function 'void part(int)':
count_triplets.cpp:55:18: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
55 | for(int j=0;j<v[i].size();j++)
| ~^~~~~~~~~~~~
count_triplets.cpp: In function 'void construct()':
count_triplets.cpp:96:26: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
96 | for(int j=0;j<v[i].size();j++)
| ~^~~~~~~~~~~~
count_triplets.cpp: In function 'void dfs(int, int)':
count_triplets.cpp:130:18: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
130 | for(int j=0;j<g[i].size();j++)
| ~^~~~~~~~~~~~
count_triplets.cpp:143:18: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
143 | for(int j=0;j<g[i].size();j++)
| ~^~~~~~~~~~~~
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
2 ms |
7504 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
2 ms |
7504 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Runtime error |
62 ms |
38728 KB |
Execution killed with signal 11 |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
3 ms |
7760 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Runtime error |
46 ms |
23112 KB |
Execution killed with signal 11 |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
3 ms |
7760 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Runtime error |
42 ms |
23068 KB |
Execution killed with signal 11 |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
2 ms |
7504 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
2 ms |
7504 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
