#include <bits/stdc++.h>
//#include <ext/pb_ds/assoc_container.hpp>
using namespace std;
//using namespace __gnu_pbds;
#define F first
#define S second
#define forn(i, n) for(int i = 0; i < n; ++i)
#define forbn(i, b, n) for(int i = b; i < n; ++i)
#define sz(v) (int)v.size()
#define pb push_back
#define mp make_pair
#define eb emplace_back
#define all(v) v.begin(), v.end()
typedef pair<int, int> ii;
typedef vector<int> vi;
typedef vector<ii> vii;
typedef long long ll;
//typedef tree<ii, null_type, less<ii>, rb_tree_tag, tree_order_statistics_node_update> ordered_set;
template <class T> inline void mineq(T &a, T b) { a = min(a, b); }
template <class T> inline void maxeq(T &a, T b) { a = max(a, b); }
const int MX = 500 * 1000 + 10;
int n;
vi gr[MX];
bool is_diam[MX];
ii far_node;
vi path;
int da[MX], db[MX];
vi diam;
int far_ch[MX];
int max_hard = -1;
int counter_hard = 0;
void dfs_far(int node, int par = 0, int depth = 0) {
da[node] = depth;
maxeq(far_node, mp(depth, node));
for(int nb: gr[node]) {
if(nb == par) continue;
dfs_far(nb, node, depth + 1);
}
}
int get_farthest(int node) {
far_node = mp(0, 0);
dfs_far(node);
return far_node.S;
}
void dfs_path(int node, int tar, int par = 0) {
db[node] = sz(path);
path.pb(node);
if(node == tar) {
for(int v: path) {
is_diam[v] = true;
diam.pb(v);
}
}
for(int nb: gr[node]) {
if(nb == par) continue;
dfs_path(nb, tar, node);
}
path.pop_back();
}
void record_path(int start, int tar) {
dfs_path(start, tar);
}
void update(int hard) {
if(hard > max_hard) {
max_hard = hard;
counter_hard = 1;
} else if(hard == max_hard) {
counter_hard += 1;
}
}
void dfs(int node, int par = 0) {
int mx1 = -1, mx2 = -1;
for(int nb: gr[node]) {
if(nb == par || is_diam[nb]) continue;
dfs(nb, node);
int val = far_ch[nb] + 1;
maxeq(far_ch[node], val);
if(val > mx1) {
mx2 = mx1;
mx1 = val;
} else if(val > mx2) {
mx2 = val;
}
}
if(mx2 > 0) {
int hard = (mx1 + mx2) * max(da[node], db[node]);
update(hard);
}
}
void count_for_diam() {
int mx1 = -1;
forn(i, sz(diam)) {
if(i > 0 && far_ch[diam[i]]) {
int val = (i + far_ch[diam[i]]) * max(mx1, sz(diam) - i - 1);
update(val);
}
maxeq(mx1, far_ch[diam[i]]);
}
}
void solve() {
cin >> n;
forn(i, n - 1) {
int a, b;
cin >> a >> b;
gr[a].pb(b);
gr[b].pb(a);
}
int a = get_farthest(1);
int b = get_farthest(a);
record_path(b, a);
// cerr << "DIAM a, b: " << a << ' ' << b << '\n';
// for(int v: diam) {
// cerr << v << ' ';
// }
// forbn(i, 1, n + 1) {
// cerr << "is diam " << i << ' ' << is_diam[i] << '\n';
// }
// forbn(i, 1, n + 1) {
// cerr << "dist_a, dist_b " << i << ' ' << da[i] << ' ' << db[i] << '\n';
// }
int mx = -1;
for(int v: diam) {
dfs(v);
maxeq(mx, far_ch[v]);
}
int val = (sz(diam) - 1) * mx;
update(val);
count_for_diam();
reverse(all(diam));
count_for_diam();
cout << max_hard << ' ' << counter_hard << '\n';
}
int main() {
ios_base::sync_with_stdio(false);
cin.tie(nullptr);
// cout.tie(nullptr);
// freopen("deleg.in", "r", stdin);
// freopen("deleg.out", "w", stdout);
int t = 1;
// cin >> t;
while(t--) {
solve();
}
}
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
6 ms |
12056 KB |
Output is correct |
| 2 |
Correct |
7 ms |
12056 KB |
Output is correct |
| 3 |
Correct |
7 ms |
12080 KB |
Output is correct |
| 4 |
Correct |
6 ms |
12072 KB |
Output is correct |
| 5 |
Correct |
6 ms |
11980 KB |
Output is correct |
| 6 |
Correct |
6 ms |
12076 KB |
Output is correct |
| 7 |
Incorrect |
6 ms |
11980 KB |
Output isn't correct |
| 8 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
6 ms |
12056 KB |
Output is correct |
| 2 |
Correct |
7 ms |
12056 KB |
Output is correct |
| 3 |
Correct |
7 ms |
12080 KB |
Output is correct |
| 4 |
Correct |
6 ms |
12072 KB |
Output is correct |
| 5 |
Correct |
6 ms |
11980 KB |
Output is correct |
| 6 |
Correct |
6 ms |
12076 KB |
Output is correct |
| 7 |
Incorrect |
6 ms |
11980 KB |
Output isn't correct |
| 8 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
6 ms |
12056 KB |
Output is correct |
| 2 |
Correct |
7 ms |
12056 KB |
Output is correct |
| 3 |
Correct |
7 ms |
12080 KB |
Output is correct |
| 4 |
Correct |
6 ms |
12072 KB |
Output is correct |
| 5 |
Correct |
6 ms |
11980 KB |
Output is correct |
| 6 |
Correct |
6 ms |
12076 KB |
Output is correct |
| 7 |
Incorrect |
6 ms |
11980 KB |
Output isn't correct |
| 8 |
Halted |
0 ms |
0 KB |
- |
