#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
const int MAXN = 2e5+7;
const int logx = 18;
vector<int> G[MAXN];
int jmp[MAXN][logx+1];
int t[MAXN];
int depth[MAXN];
int rep[MAXN];
int val[MAXN];
pair<ll, int> res[MAXN];
int n;
void connect(int a, int b){
//cout << "connect: " << a << " " << b << "\n";
G[a].push_back(b);
G[b].push_back(a);
}
void dfs(int v, int p){
depth[v] = depth[p] + 1;
jmp[v][0] = p;
for(int k = 1; k <=logx; k++)
jmp[v][k] = jmp[jmp[v][k-1]][k-1];
for(auto u : G[v])
if(u != p) dfs(u, v);
}
int lca(int a, int b){
if(depth[a] > depth[b]) swap(a, b);
for(int k = logx; k >= 0; k--)
if(depth[jmp[b][k]] >= depth[a])
b = jmp[b][k];
if(a == b)
return a;
for(int k = logx; k >= 0; k--){
if(jmp[a][k] != jmp[b][k]){
a = jmp[a][k];
b = jmp[b][k];
}
}
return jmp[a][0];
}
ll get_dist(int a, int b){
return depth[a] + depth[b] - 2*depth[lca(a, b)];
}
int Find(int a){
if(rep[a] == a)
return a;
return rep[a] = Find(rep[a]);
}
void Union(int a, int b){
//cout << "a: " << a << " b: " << b << "\n";
a = Find(a);
b = Find(b);
if(a == b) return;
ll dist = get_dist(a, res[b].second);
pair<ll, int> sum = {res[b].first + dist, a};
if(val[a] < val[b]) swap(a, b);
rep[b] = a;
val[a] += val[b];
res[a] = max({res[b], res[a], sum});
}
void merge(int v){
for(auto u : G[v])
if(u < v) Union(v, u);
//cout << "res: " << v << " " << res[Find(v)].first << "\n";
}
int main(){
ios_base::sync_with_stdio(0);
cin.tie(0);
cin >> n;
for(int i = 1; i <= n; i++)
cin >> t[i];
for(int i = 1; i < n; i++){
int a, b;
cin >> a >> b;
connect(t[a], t[b]);
}
dfs(n, n);
for(int i = 1; i <= n; i++){
rep[i] = i;
val[i] = 1;
res[i].second = i;
}
for(int i = 1; i <= n; i++) merge(i);
cout << res[Find(n)].first << "\n";
}
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
2 ms |
9560 KB |
Output is correct |
2 |
Incorrect |
2 ms |
9564 KB |
Output isn't correct |
3 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
2 ms |
9560 KB |
Output is correct |
2 |
Incorrect |
2 ms |
9564 KB |
Output isn't correct |
3 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
2 ms |
9560 KB |
Output is correct |
2 |
Incorrect |
2 ms |
9564 KB |
Output isn't correct |
3 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
2 ms |
9560 KB |
Output is correct |
2 |
Incorrect |
2 ms |
9564 KB |
Output isn't correct |
3 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
2 ms |
9560 KB |
Output is correct |
2 |
Incorrect |
2 ms |
9564 KB |
Output isn't correct |
3 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
2 ms |
9692 KB |
Output is correct |
2 |
Correct |
2 ms |
9564 KB |
Output is correct |
3 |
Incorrect |
159 ms |
36140 KB |
Output isn't correct |
4 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
2 ms |
9560 KB |
Output is correct |
2 |
Incorrect |
2 ms |
9564 KB |
Output isn't correct |
3 |
Halted |
0 ms |
0 KB |
- |