/** made by amunduzbaev **/
#include <bits/stdc++.h>
using namespace std;
#define ff first
#define ss second
#define pb push_back
#define mp make_pair
#define ub upper_bound
#define lb lower_bound
#define ll long long
#define ld long double
#define pii pair<int, int>
#define pll pair<ll, ll>
#define sz(x) (int)x.size()
#define all(x) x.begin(), x.end()
#define rall(x) x.rbegin(),x.rend()
#define fastios ios::sync_with_stdio(0);cin.tie(0);cout.tie(0);
#define vll vector<ll>
#define vii vector<int>
#define vpii vector<pii>
#define vpll vector<pll>
#define cnt(a)__builtin_popcount(a)
template<class T> bool umin(T& a, const T& b) {return a > b? a = b, true:false;}
template<class T> bool umax(T& a, const T& b) {return a < b? a = b, true:false;}
const int N = 21;
const int mod = 1e9+7;
const ll inf = 1e18;
const ld Pi = acos(-1);
int s, n, m, k;
pii ans;
vii edges[N];
stack<int> ss;
bool f, used[N], cyc[N];
pii mxd[N];
vii cc;
void dfs(int u, int p){
if(!cc.empty()) return;
if(used[u]){
while(!ss.empty() && ss.top() != u){
cc.pb(ss.top());
ss.pop();
}f = 1;
cc.pb(u);return;
}
used[u] = 1;
ss.push(u);
for(auto x:edges[u]) if(x != p) dfs(x, u);
if(!ss.empty()) ss.pop();
}
pii merge(pii a, pii b){
if(a.ff > b.ff) return a;
if(b.ff > a.ff) return b;
return mp(a.ff, a.ss + b.ss);
}
void find_tree(int u, int p, int dd){
vpii tmp;
for(auto x:edges[u]){
if(cyc[x] || x == p) continue;
find_tree(x, u, dd+1);
tmp.pb(mxd[x]);
mxd[u] = merge(mxd[x], mxd[u]);
}
sort(all(tmp));
int n = sz(tmp);
if(n >= 2){
pii b = tmp[n-2], a = tmp[n-1], c = {a.ff + b.ff, 0};
for(int i=0;i<n;i++){
if(tmp[i].ff == b.ff) c.ss += tmp[i].ss;
}
if(a.ff != b.ff){
c.ss *= a.ss;
ans = merge(ans, c);
}else{
c.ss *= c.ss;
for(auto x:tmp){
if(x.ff == b.ff) c.ss -= x.ss * x.ss;
}
c.ss /= 2;
ans = merge(c, ans);
}
}else { ans = merge(ans, mxd[u]); }
mxd[u].ff++; //, mxd[u].ss++;
}
void solve(){
cin>>n;
for(int i=0;i<n;i++){
int a, b;
cin>>a>>b;
edges[a].pb(b);
edges[b].pb(a);
}
for(int i=1;i<=n;i++){
mxd[i] = {0, 1};
}
dfs(1, -1);
int cyclen = sz(cc);
for(auto x:cc) cyc[x] = 1;
for(int i=1;i<=n;i++){
if(cyc[i]){
find_tree(i, -1, 0);
//mxd[i].ff--;
}
}
for(int i=0;i<cyclen;i++){
for(int j=i+1;j<cyclen;j++){
int dis = min(j-i, cyclen - (j-i));
pii tmp = {mxd[cc[i]].ff + mxd[cc[j]].ff + dis, mxd[cc[i]].ss * mxd[cc[j]].ss};
if(j-i == cyclen - (j-i)) tmp.ss *= 2;
ans = merge(ans, tmp);
}
}
cout<<ans.ss; //ff<<" "<<ans.ss<<endl;
return;
}
/*
13
1 2
2 3
3 4
4 5
5 1
5 12
5 13
12 11
12 10
2 6
6 7
3 8
3 9
*/
int main(){
fastios
int t = 0;
if(!t) solve();
else {
cin>>t;
while (t--) solve();
}
return 0;
}
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
1 ms |
364 KB |
Output is correct |
| 2 |
Incorrect |
0 ms |
364 KB |
Output isn't correct |
| 3 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Runtime error |
1 ms |
492 KB |
Execution killed with signal 11 (could be triggered by violating memory limits) |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Runtime error |
1 ms |
492 KB |
Execution killed with signal 11 (could be triggered by violating memory limits) |
| 2 |
Halted |
0 ms |
0 KB |
- |
