#include<iostream>
#include<algorithm>
#include<iomanip>
#include<cmath>
#include<cstring>
#include<vector>
#include<queue>
#include<stack>
#include<tuple>
#include<set>
#include<map>
#include<random>
#include<chrono>
using namespace std;
const long long MAX_N=5e5+5;
long long maxd[MAX_N];
long long cntd[MAX_N];
long long maxd2[MAX_N];
long long maxdup[MAX_N];
vector<long long>g[MAX_N];
long long n;
long long cnt;
long long ans;
long long depth[MAX_N];
void dfsdown(long long u,long long par)
{
for(long long v:g[u])
{
if(v==par)continue;
depth[v]=depth[u]+1;
dfsdown(v,u);
if(maxd[v]+1>maxd[u])
{
maxd2[u]=maxd[u];
maxd[u]=maxd[v]+1;
cntd[u]=cntd[v];
}
else if(maxd[v]+1==maxd[u])
{
maxd2[u]=maxd[u];
cntd[u]+=cntd[v];
}
}
if(g[u].size()==1)cntd[u]=1;
}
long long dp[MAX_N];
void dfsup(long long u,long long par)
{
for(long long v:g[u])
{
if(v==par)continue;
long long cur=maxd[u];
if(maxd[v]+1==maxd[u])cur=maxd2[u];
dp[v]=max(dp[u],cur);
maxdup[v]=max(maxdup[u],cur)+1;
dfsup(v,u);
}
}
long long eachtwo(vector<long long>& v)
{
long long sum=0;
long long pairs=0;
for(long long x:v)sum+=x;
for(long long x:v)
{
sum-=x;
pairs+=(x*sum);
}
return pairs;
}
void dfs(long long u,long long par)
{
vector<pair<long long,long long>>V;//depth,cnt
vector<pair<long long,long long>>all;
vector<pair<long long,long long>>otherV;
long long up=maxdup[u],curans=0,curcnt=0;
for(long long v:g[u])
{
if(v==par)continue;
dfs(v,u);
all.push_back({maxd[v]+1,cntd[v]});
}
if(g[u].size()==1)return;
sort(all.begin(),all.end());
V.push_back(all[0]);
otherV.push_back({all[0].first,1});
for(long long i=1;i<all.size();i++)
{
if(all[i].first==all[i-1].first)
{
V.back().second+=all[i].second;
otherV.back().second++;
}
else {V.push_back(all[i]);otherV.push_back({all[i].first,1});}
}
if(otherV.back().second>=3)
{
long long b=V.back().first;
vector<long long>only;
for(long long v:g[u])
{
if(v==par)continue;
if(maxd[v]+1==b)only.push_back(cntd[v]);
}
long long eachtwob=eachtwo(only);
curans=2*b*b;
curcnt=eachtwob;
}
else
{
if(otherV.back().second==2)
{
if(V.size()>=2)
{
long long b=V.back().first,cb=V.back().second;
long long a=V[V.size()-2].first,ca=V[V.size()-2].second;
curans=b*(a+b);
curcnt=ca*cb;
}
}
else
{
if(V.size()==2)
{
if(otherV[0].second>=2)
{
long long b=V[1].first;
long long a=V[0].first;
vector<long long>only;
for(long long v:g[u])
{
if(v==par)continue;
if(maxd[v]+1==a)only.push_back(cntd[v]);
}
long long eachtwoa=eachtwo(only);
curans=2*a*b;
curcnt=eachtwoa;
}
}
else if(V.size()>2)
{
long long b=V.back().first,cb=V.back().second;
long long a=V[V.size()-2].first,ca=V[V.size()-2].second;
long long c=V[V.size()-3].first,cc=V[V.size()-3].second;
curans=b*(a+c);
curcnt=cc*ca;
}
}
}
///without up
if(otherV.back().second>=2)
{
long long b=V.back().first;
vector<long long>only;
for(long long v:g[u])
{
if(v==par)continue;
if(maxd[v]+1==b)only.push_back(cntd[v]);
}
long long eachtwob=eachtwo(only);
if(2*b*up>curans)
{
curans=2*b*up;
curcnt=eachtwob;
}
else if(2*b*up==curans)
{
curcnt+=eachtwob;
}
}
else
{
if(V.size()>=2)
{
long long b=V.back().first,cb=V.back().second;
long long a=V[V.size()-2].first,ca=V[V.size()-2].second;
if((a+b)*up>curans)
{
curans=(a+b)*up;
curcnt=ca*cb;
}
else if((a+b)*up==curans)
{
curcnt+=ca*cb;
}
}
}
///with up
if(curans>ans)
{
ans=curans;
cnt=curcnt;
}
else if(curans==ans)
{
cnt+=curcnt;
}
}
pair<long long,long long>diam(long long u,long long par)
{
pair<long long,long long>res={u,0};
for(long long v:g[u])
{
if(v==par)continue;
if(diam(v,u).second+1>res.second)
{
res=diam(v,u);
res.second++;
}
}
return res;
}
///
void solvefor(long long root)
{
for(long long i=1;i<=n;i++)
{
if(g[i].size()!=1 or i==root)continue;
long long curhardness=depth[i]*dp[i];
if(curhardness>ans)
{
ans=curhardness;
cnt=1;
}
else if(curhardness==ans)cnt++;
}
}
signed main()
{
ios_base::sync_with_stdio(0);
cin.tie(NULL);
cout.tie(NULL);
cin>>n;
for(long long i=1;i<n;i++)
{
long long u,v;
cin>>u>>v;
g[u].push_back(v);
g[v].push_back(u);
}
long long distant=diam(1,0).first;
long long root=diam(distant,0).first;
dfsdown(root,0);
dfsup(root,0);
dfs(root,0);
solvefor(root);
if(ans==0)cnt=1;
cout<<ans<<" "<<cnt<<"\n";
return 0;
}
Compilation message
road.cpp: In function 'void dfs(long long int, long long int)':
road.cpp:100:24: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<std::pair<long long int, long long int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
100 | for(long long i=1;i<all.size();i++)
| ~^~~~~~~~~~~
road.cpp:164:44: warning: unused variable 'cb' [-Wunused-variable]
164 | long long b=V.back().first,cb=V.back().second;
| ^~
| # |
결과 |
실행 시간 |
메모리 |
Grader output |
| 1 |
Correct |
2 ms |
13656 KB |
Output is correct |
| 2 |
Correct |
2 ms |
14684 KB |
Output is correct |
| 3 |
Correct |
2 ms |
13496 KB |
Output is correct |
| 4 |
Correct |
2 ms |
14684 KB |
Output is correct |
| 5 |
Correct |
2 ms |
13488 KB |
Output is correct |
| 6 |
Correct |
2 ms |
13660 KB |
Output is correct |
| 7 |
Execution timed out |
2059 ms |
14824 KB |
Time limit exceeded |
| 8 |
Halted |
0 ms |
0 KB |
- |
| # |
결과 |
실행 시간 |
메모리 |
Grader output |
| 1 |
Correct |
2 ms |
13656 KB |
Output is correct |
| 2 |
Correct |
2 ms |
14684 KB |
Output is correct |
| 3 |
Correct |
2 ms |
13496 KB |
Output is correct |
| 4 |
Correct |
2 ms |
14684 KB |
Output is correct |
| 5 |
Correct |
2 ms |
13488 KB |
Output is correct |
| 6 |
Correct |
2 ms |
13660 KB |
Output is correct |
| 7 |
Execution timed out |
2059 ms |
14824 KB |
Time limit exceeded |
| 8 |
Halted |
0 ms |
0 KB |
- |
| # |
결과 |
실행 시간 |
메모리 |
Grader output |
| 1 |
Correct |
2 ms |
13656 KB |
Output is correct |
| 2 |
Correct |
2 ms |
14684 KB |
Output is correct |
| 3 |
Correct |
2 ms |
13496 KB |
Output is correct |
| 4 |
Correct |
2 ms |
14684 KB |
Output is correct |
| 5 |
Correct |
2 ms |
13488 KB |
Output is correct |
| 6 |
Correct |
2 ms |
13660 KB |
Output is correct |
| 7 |
Execution timed out |
2059 ms |
14824 KB |
Time limit exceeded |
| 8 |
Halted |
0 ms |
0 KB |
- |
