#include<bits/stdc++.h>
#define TASKNAME "codeforce"
#define pb push_back
#define pli pair<int,int>
#define fi first
#define se second
#define fastio ios_base::sync_with_stdio(false); cin.tie(NULL);
using namespace std;
using ll=long long;
const ll maxN=2e5+10;
const ll inf=1e18;
const ll mod=1e9+7;
stack< int > stt;
bool minimize(int &a, int b){ if (a>b) a=b; else return false; return true; }
bool maximize(int &a, int b){ if (a<b) a=b; else return false; return true; }
ll low[maxN],num[maxN],Time=0;
vector<ll>g[maxN];
ll cnt=0;
int lc[maxN];
vector<ll>bcc[maxN];
void DFS(int u){
low[u]=num[u]=++Time;
for (auto v:g[u]){
if (num[v]) low[u]=min(low[u], num[v]);
else {
stt.push(u);
DFS(v);
low[u]=min(low[u], low[v]);
if (low[v]>=num[u]) {
cnt++;
do {
v=stt.top(); stt.pop();
if (maximize(lc[v], cnt)==true) bcc[cnt].pb(v);
} while (u!=v);
}
}
}
stt.push(u);
}
ll n,m,u,v;
ll ct[maxN],val[maxN],ans=0,vc=0;
vector<ll>adj[maxN];
void dfs(ll u,ll p)
{
ct[u]=val[u];
for(auto v:adj[u])
{
if(v!=p)
{
dfs(v,u);
ct[u]+=ct[v];
}
}
for(auto v:adj[u])
{
if(v!=p)
{
vc+=ct[v]*val[u]*(ct[u]-ct[v]-val[u]);
}
}
vc+=(ct[u]-val[u])*val[u]*(n-ct[u]);
}
ll val2[maxN];
vector<ll>vec[maxN];
void solve()
{
cin >> n >> m;
for(int i=1;i<=m;i++)
{
cin >> u >> v;
g[u].pb(v);
g[v].pb(u);
}
DFS(1);
for(int i=1;i<=cnt;i++)
{
for(auto zz:bcc[i])
{
vec[zz].pb(i);
}
if(bcc[i].size()>=3)
{
ll x=bcc[i].size();
ans+=x*(x-1)*(x-2);
}
val[i]=bcc[i].size();
}
for(int i=1;i<=n;i++)
{
if(vec[i].size()==1) continue;
cnt++;
for(auto zz:vec[i])
{
adj[cnt].pb(zz);
adj[zz].pb(cnt);
val[zz]--;
}
val[cnt]++;
}
ll sum=0;
for(int i=1;i<=cnt;i++)
{
val2[i]=val[i]*(val[i]-1);
sum+=val2[i];
}
dfs(1,1);
vc*=2;
ans+=vc;
//cout << ans << '\n';
for(int i=1;i<=cnt;i++)
{
vc=sum-val2[i];
for(auto j:adj[i])
{
vc-=val2[j];
}
ans+=vc*val[i];
vc=n-val[i];
for(auto j:adj[i])
{
vc-=val[j];
}
ans+=vc*val2[i];
}
cout << ans;
}
int main()
{
fastio
//freopen(TASKNAME".INP","r",stdin);
//freopen(TASKNAME".OUT","w",stdout);
solve();
}
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Incorrect |
11 ms |
19156 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Incorrect |
11 ms |
19156 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
76 ms |
38788 KB |
Output is correct |
2 |
Correct |
78 ms |
38708 KB |
Output is correct |
3 |
Incorrect |
68 ms |
32896 KB |
Output isn't correct |
4 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Incorrect |
12 ms |
19272 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Incorrect |
153 ms |
41716 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Incorrect |
11 ms |
19380 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Incorrect |
143 ms |
41660 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Incorrect |
11 ms |
19156 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Incorrect |
11 ms |
19156 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |