#include <bits/stdc++.h>
#define FIXED_FLOAT(x) std::fixed <<std::setprecision(20) << (x)
#define all(v) (v).begin(), (v).end()
using namespace std;
#define forn(i,n) for (int i = 0; i < (n); ++i)
#define rforn(i, n) for(int i = (n) - 1;i >= 0;--i)
#define sz(x) (int)x.size()
#define ff first
#define se second
#define mp make_pair
using ll = long long;
int mod = (ll)1e9 + 7;
const int INF = 1e9 + 1;
const int N = 2e5 + 100;
const double eps = 1e-7;
template <class T> using V = vector<T>;
template <class T> using VV = V<V<T>>;
template<class T, size_t SZ> using AR = array<T, SZ>;
template<class T> using PR = pair<T, T>;
template <typename XPAX>
bool ckma(XPAX &x, XPAX y) {
return (x < y ? x = y, 1 : 0);
}
template <typename XPAX>
bool ckmi(XPAX &x, XPAX y) {
return (x > y ? x = y, 1 : 0);
}
void __print(int x) {cerr << x;}
void __print(long x) {cerr << x;}
void __print(long long x) {cerr << x;}
void __print(unsigned x) {cerr << x;}
void __print(unsigned long x) {cerr << x;}
void __print(unsigned long long x) {cerr << x;}
void __print(float x) {cerr << x;}
void __print(double x) {cerr << x;}
void __print(long double x) {cerr << x;}
void __print(char x) {cerr << '\'' << x << '\'';}
void __print(const char *x) {cerr << '\"' << x << '\"';}
void __print(const string &x) {cerr << '\"' << x << '\"';}
void __print(bool x) {cerr << (x ? "true" : "false");}
template<typename T, typename V>
void __print(const pair<T, V> &x) {cerr << '{'; __print(x.first); cerr << ','; __print(x.second); cerr << '}';}
template<typename T>
void __print(const T &x) {int f = 0; cerr << '{'; for (auto &i: x) cerr << (f++ ? "," : ""), __print(i); cerr << "}";}
void _print() {cerr << "]\n";}
template <typename T, typename... V>
void _print(T t, V... v) {__print(t); if (sizeof...(v)) cerr << ", "; _print(v...);}
#define debug(x...) cerr << "[" << #x << "] = ["; _print(x)
int n, dep[N], pre[N], bdis[N];
PR<ll> ret{-1,0};
V<int> g[N];
void ck(PR<ll> x) {
if(x.ff > ret.ff)ret = x;
else if(x.ff==ret.ff)ret.se += x.se;
}
void dfs(int v) {
for(auto c : g[v]) if(c != pre[v]) {
dep[c] = dep[v]+1;
pre[c]= v;
dfs(c);
}
}
void genDist(int v) {
memset(dep, 0, sizeof(dep));
pre[v]=-1;
dfs(v);
}
int diam() {
genDist(1);
int w = 0;
for(int i = 1;i <= n;++i) if(dep[w] < dep[i]) w = i;
genDist(w);
for(int i = 1;i <= n;++i) if(dep[w] < dep[i]) w = i;
return dep[w];
}
V<int> C;
int t;
PR<int> dfs(int a, int b, int c) {
V<PR<int>> v;
PR<int> z{0,0};
for(auto i : g[a]) if(i!=b) {
PR<int> t = dfs(i, a, c+1);
t.ff++;
v.push_back(t);
if(t.ff > z.ff) z.se=z.ff, z.ff=t.ff;
else if(t.ff > z.se)z.se = t.ff;
}
int o = 0;
for(auto i : g[a]) if(i != b) {
if(v[o].ff==z.ff)bdis[i]=z.se;
else bdis[i]=z.ff;
o++;
}
if(sz(v)==0)v.push_back({0,1});
if(sz(v)==1)return v[0];
sort(v.rbegin(), v.rend());
int id = 0, sm =v[0].se;
while(id+1 < sz(v) && v[id+1].ff==v[id].ff)
sm += v[++id].se;
if(id > 0) {
ll t = sm * 1ll * (sm - 1) / 2;
forn(i,id+1)sm -= v[i].se *1ll * (v[i].se - 1) / 2;
ck({1ll*v[0].ff*2*c, t});
}
else {
id = 1;
ll sm2 = 0;
while(id < sz(v) && v[id].ff==v[1].ff) sm2 += v[id++].se;
ck({1ll*(v[0].ff+v[1].ff), sm2*sm});
}
return {v[0].ff, sm};
}
V<int> genCenter() {
t = diam();
int w = 0;
for(int i = 1;i <= n;++i) if(dep[w] < dep[i])w = i;
forn(i,t/2)w = pre[w];
if(t & 1) return {w, pre[w]};
else return {w};
}
V<PR<int>> tmp;
void goNoCenter() {
if(sz(C) == 2) {
tmp.push_back(dfs(C[0],C[1],t/2+1));
tmp.push_back(dfs(C[1], C[0], t/2+1));
}
else {
for(auto c : g[C[0]]) tmp.push_back(dfs(c,C[0],t/2+1));
}
}
V<PR<int>> z[2];
void dfs2(int v, int p, int cdis, int cmax, int i) {
bool isleaf = 1;
for(auto c : g[v]) {
if(c != p) {
isleaf=0;
dfs2(c, v, cdis+1, max(cmax, bdis[v]),i);
}
}
if(isleaf) z[i].push_back({cmax, cdis});
}
int S[2][500001];
void goCenter() {
V<int> w;
ll sm = 0, bad = 0;
int mx = 0;
if(sz(C)==2) {
w = C;
}
else {
forn(i, sz(tmp)) if(tmp[i].ff == t / 2 -1) {
w.push_back(g[C[0]][i]);
sm += tmp[i].se;
bad += (ll)tmp[i].se * (tmp[i].se-1)/2;
}else {
ckma(mx, tmp[i].ff+1);
}
}
//debug(w);
if(sz(w)>2) {
ck({1ll*t*t/2, sm*(sm-1)/2-bad});
return;
}
if(sz(C)==2) {
dfs2(C[0], C[1], 0, 0,0);
dfs2(C[1], C[0], 1,0,1);
}
else {
dfs2(w[0],C[0],1,mx,0);
dfs2(w[1],C[0],1,mx,1);
}
sort(all(z[0]));sort(all(z[1]));
//debug(ret);
forn(k,2) for(auto c : z[k]) S[k][c.se]++;
AR<int, 2> t = {500000, 500000};
//debug(z[0], z[1]);
while(sz(z[0]) && sz(z[1])) {
forn(k,2) while(!S[k][t[k]])t[k]--;
if(z[0].back().ff < z[1].back().ff) {
ck({1ll*(t[0]+z[1].back().se)*z[1].back().ff, S[0][t[0]]});
S[1][z[1].back().se]--;z[1].pop_back();
}
else {
//debug(S[1][t[1]]);
ck({1ll*(t[1]+z[0].back().se)*z[0].back().ff, S[1][t[1]]});
S[0][z[0].back().se]--;z[0].pop_back();
}
}
//debug(ret);
}
void solve() {
cin >> n;
forn(i, n-1) {
int a, b;
cin >> a >> b;
g[a].push_back(b);
g[b].push_back(a);
}
C = genCenter();
goNoCenter();
//debug(ret, t);
//debug(C);
goCenter();
//debug(tmp);
cout << ret.ff << ' ' << ret.se << '\n';
}
void test_case() {
int t;
cin >> t;
forn(p, t) {
//cout << "Case #" << p + 1 << ": ";
solve();
}
}
int main() {
ios::sync_with_stdio(false);
cin.tie(0);
solve();
}
| # |
결과 |
실행 시간 |
메모리 |
Grader output |
| 1 |
Correct |
5 ms |
5804 KB |
Output is correct |
| 2 |
Correct |
3 ms |
5792 KB |
Output is correct |
| 3 |
Correct |
5 ms |
5708 KB |
Output is correct |
| 4 |
Correct |
4 ms |
5804 KB |
Output is correct |
| 5 |
Correct |
5 ms |
5708 KB |
Output is correct |
| 6 |
Correct |
4 ms |
5708 KB |
Output is correct |
| 7 |
Incorrect |
4 ms |
5804 KB |
Output isn't correct |
| 8 |
Halted |
0 ms |
0 KB |
- |
| # |
결과 |
실행 시간 |
메모리 |
Grader output |
| 1 |
Correct |
5 ms |
5804 KB |
Output is correct |
| 2 |
Correct |
3 ms |
5792 KB |
Output is correct |
| 3 |
Correct |
5 ms |
5708 KB |
Output is correct |
| 4 |
Correct |
4 ms |
5804 KB |
Output is correct |
| 5 |
Correct |
5 ms |
5708 KB |
Output is correct |
| 6 |
Correct |
4 ms |
5708 KB |
Output is correct |
| 7 |
Incorrect |
4 ms |
5804 KB |
Output isn't correct |
| 8 |
Halted |
0 ms |
0 KB |
- |
| # |
결과 |
실행 시간 |
메모리 |
Grader output |
| 1 |
Correct |
5 ms |
5804 KB |
Output is correct |
| 2 |
Correct |
3 ms |
5792 KB |
Output is correct |
| 3 |
Correct |
5 ms |
5708 KB |
Output is correct |
| 4 |
Correct |
4 ms |
5804 KB |
Output is correct |
| 5 |
Correct |
5 ms |
5708 KB |
Output is correct |
| 6 |
Correct |
4 ms |
5708 KB |
Output is correct |
| 7 |
Incorrect |
4 ms |
5804 KB |
Output isn't correct |
| 8 |
Halted |
0 ms |
0 KB |
- |
