#include<bits/stdc++.h>
using namespace std;
#define rep(i,a,b) for(int i = a; i<int(b);++i)
#define all(v) v.begin(),v.end()
#define sz(v) v.size()
#define trav(a,c) for(auto a: c)
typedef long long ll;
typedef vector<ll> vi;
typedef pair<ll,ll> pii;
vi dfsNum;
vi dfsLow;
ll currDfsNum = 0;
vector<vi> e;
set<pii> bridges;
void dfs(ll v, ll l){
if(dfsNum[v]!=-1) return;
dfsNum[v] = dfsLow[v] = currDfsNum++;
rep(i,0,e[v].size()){
if(e[v][i]==l) continue;
dfs(e[v][i],v);
dfsLow[v] = min(dfsLow[v],dfsLow[e[v][i]]);
}
}
vector<vi> cycles;
vi cycleIndices;
vector<bool> seen;
void getCycle(ll v){
if(seen[v]) return;
seen[v] = true;
cycles[cycles.size()-1].push_back(v);
cycleIndices[v] = cycles.size()-1;
rep(i,0,e[v].size()){
if(bridges.find({v,e[v][i]})==bridges.end())
getCycle(e[v][i]);
}
}
vector<vi> treeE;
vector<vi> dp;
ll getNum(ll v,ll l, ll toPlace){
//cout<<v<<" "<<toPlace-1<<endl;
if(dp[v][toPlace-1]!=-1) return dp[v][toPlace-1];
ll ans = 0;
if(toPlace==1)
ans += cycles[v].size();
ll childSum = 0;
rep(i,0,treeE[v].size())
if(treeE[v][i] != l)
childSum += getNum(treeE[v][i],v,1);
rep(i,0,treeE[v].size()){
if(treeE[v][i] == l) continue;
if(toPlace==1)
ans += getNum(treeE[v][i],v,1);
if(toPlace==2){
ans += getNum(treeE[v][i],v,1)*cycles[v].size();
ans += getNum(treeE[v][i],v,2);
}
if(toPlace==3){
ll childNum = getNum(treeE[v][i],v,1);
ans += childNum*(childSum - childNum)*cycles[v].size();
ans += getNum(treeE[v][i],v,2)*cycles[v].size()*2;
ans += getNum(treeE[v][i],v,3);
}
}
return dp[v][toPlace-1] = ans;
}
int main(){
cin.sync_with_stdio(false);
ll n,m;
cin>>n>>m;
e.resize(n);
dfsNum.resize(n,-1);
dfsLow.resize(n,-1);
vector<pii> edges(m);
rep(i,0,m){
ll a,b;
cin>>a>>b;
--a; --b;
edges[i] = {a,b};
e[a].push_back(b);
e[b].push_back(a);
}
rep(i,0,n)
dfs(i,-1);
//cout<<endl<<endl;
rep(i,0,n){
//cout<<i+1<<": "<<dfsNum[i]<<" "<<dfsLow[i]<<endl;
}
rep(i,0,m){
ll a,b;
tie(a,b) = edges[i];
if(dfsNum[a]<dfsNum[b]&&dfsLow[b]==dfsNum[b]){
bridges.insert({a,b});
bridges.insert({b,a});
}
if(dfsNum[b]<dfsNum[a]&&dfsLow[a]==dfsNum[a]){
bridges.insert({a,b});
bridges.insert({b,a});
}
}
cycleIndices.resize(n);
seen.resize(n);
rep(i,0,n){
if(seen[i]) continue;
cycles.push_back(vi(0));
getCycle(i);
}
treeE.resize(cycles.size());
trav(bridge,bridges){
//cout<<bridge.first+1<<" "<<bridge.second+1<<endl;
if(bridge.first<bridge.second){
ll a = cycleIndices[bridge.first];
ll b = cycleIndices[bridge.second];
treeE[a].push_back(b);
treeE[b].push_back(a);
}
}
ll ans = 0;
rep(i,0,cycles.size()){
ll sz = cycles[i].size();
ans += (sz)*(sz-1)*(sz-2);
ans += (sz-1)*(sz-1)*(n-sz)*2;
}
dp.resize(cycles.size(),vi(3,-1));
ans += getNum(0,-1,3);
cout<<ans<<endl;
}
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
2 ms |
376 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
2 ms |
376 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
205 ms |
17000 KB |
Output is correct |
| 2 |
Correct |
165 ms |
18240 KB |
Output is correct |
| 3 |
Incorrect |
420 ms |
31112 KB |
Output isn't correct |
| 4 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
6 ms |
31112 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
719 ms |
45380 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
7 ms |
45380 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
768 ms |
46796 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
2 ms |
376 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
2 ms |
376 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
