Codeforces 600E - Lomsat gelral

dsu on tree

#include <bits/stdc++.h>
/*
#include<ext/pb_ds/assoc_container.hpp>
#include<ext/pb_ds/hash_policy.hpp>
*/
using namespace std;

const double eps = 1e-10;
const double pi = 3.1415926535897932384626433832795;
const double eln = 2.718281828459045235360287471352;

#define f(i, a, b) for (int i = a; i <= b; i++)
#define scan(x) scanf("%d", &x)
#define mp make_pair
#define pb push_back
#define lowbit(x) (x&(-x))

#define fi first
#define se second
#define SZ(x) int((x).size())
#define all(x) x.begin(), x.end()
#define rall(x) x.rbegin(), x.rend()
#define summ(a) (accumulate(all(a), 0ll))

typedef unsigned long long ull;
typedef pair<int,int> pii;
typedef vector<int> vi;

using ll=long long;

ll n,c[(int)1e5+9],sz[(int)1e5+9],son[(int)1e5+9],cnt[(int)1e5+9],mx,res,ans[(int)1e5+9];
vector<int> g[(int)1e5+9];

void dfs(int u,int fa){
    for(auto it:g[u])if(it!=fa)dfs(it,u),sz[u]+=sz[it],son[u]=sz[son[u]]<sz[it]?it:son[u];
    sz[u]+=1;
}

void cal(int u,int fa,int val,int bson){
    cnt[c[u]]+=val;
    if(cnt[c[u]]>mx)res=c[u],mx=cnt[c[u]];
    else if(cnt[c[u]]==mx)res+=c[u];
    for(auto it:g[u]){
        if(it!=fa&&it!=bson)cal(it,u,val,bson);
    }
}

void dfs2(int u,int fa,int opt){
    for(auto it:g[u])if(it!=fa&&it!=son[u])dfs2(it,u,1);
    if(son[u])dfs2(son[u],u,0);
    cal(u,fa,1,son[u]);
    ans[u]=res;
    if(opt)cal(u,fa,-1,0),res=0,mx=0;
}

int main()
{
    ios::sync_with_stdio(false);
    cin.tie(0);
    cin>>n;
    for(int i=1;i<=n;++i)cin>>c[i];
    for(int i=1,x,y;i<n;++i){
        cin>>x>>y;
        g[x].push_back(y),g[y].push_back(x);
    }
    dfs(1,0);
    dfs2(1,0,0);
    for(int i=1;i<=n;++i)cout<<ans[i]<<" \n"[i==n];
    return 0;
}