# | Time | Username | Problem | Language | Result | Execution time | Memory |
---|---|---|---|---|---|---|---|
1095783 | lampooppp | Cat Exercise (JOI23_ho_t4) | C++17 | 0 ms | 0 KiB |
This submission is migrated from previous version of oj.uz, which used different machine for grading. This submission may have different result if resubmitted.
#include <bits/stdc++.h>
using namespace std;
const int N=2e5+10;
int up[N+1][20], h[N+1];
vector<int> adj[N+1];
bool vis[N+1];
void dfs(int x)
{
vis[u]=1;
for(int v : adj[u])
{
if(vis[v]) continue;
h[v]=h[u]+1;
up[v][0]=u;
for(int i=1;i<20;++i) up[v][i] = up[up[v][i-1]][i-1];
dfs(v);
}
}
int lca(int u,int v)
{
if(h[u]<h[v]) swap(u,v);
int k = h[u]-h[v];
for(int i=0;i<20;++i)
{
if(k>>i&1) u=up[u][i];
}
if(u==v) return u;
k=__lg(h[u]);
for(k;k>=0;--k)
{
if(up[u][k]!=up[v][k])
{
u=up[u][k];
v=up[v][k];
}
}
return up[u][0];
}
int a[N+1];
int dp[N+1];
int lab[N+1];
int mx[N+1];
int main()
{
int n;
cin >> n;
for(int i=1;i<=n;++i)
{
cin >> a[i];
lab[i]=-1;
mx[i]=i;
}
for(int i=1;i<n;++i)
{
int u,v;
cin >> u >> v;
adj[a[u]].push_back(a[v]);
adj[a[v]].push_back(a[u]);
}
h[1]=1;
dfs(1);
dp[1]=0;
for(int i=2;i<=n;++i)
{
for(int v : adj[i])
{
if(v<i)
{
int k = mx[findset(v)];
dp[i]=max(dp[i],dp[k]+dis(k,i));
unite(v,i);
}
}
}
}