Educational Codeforces Round 2 E Lomsat gelral(启发式合并)

时间:2022-10-13 22:09:43

思路:维护每个子树颜色最多的数量以及每个颜色拥有的数量,然后启发式合并一波


#include<bits/stdc++.h>
using namespace std;
#define LL long long
const int maxn = 1e5+7;
vector<int>e[maxn];
int n,c[maxn],num[maxn]; //
LL ans[maxn];
map<int,int>cnt[maxn]; //cnt[u][i] 以u的子树有多少种颜色i

void dfs(int u,int fa)
{
num[u]=1;
ans[u]=c[u];
cnt[u][c[u]]=1;
for(int i = 0;i<e[u].size();i++)
{
int v= e[u][i];
if(v==fa)continue;
dfs(v,u);
if(cnt[u].size()<cnt[v].size())
{
swap(cnt[u],cnt[v]);
swap(num[u],num[v]);
ans[u]=ans[v];
}
for(map<int,int>::iterator it = cnt[v].begin();it!=cnt[v].end();it++)
{
cnt[u][it->first]+=it->second;
if(cnt[u][it->first] > num[u])
{
ans[u]=it->first;
num[u]=cnt[u][it->first];
}
else if (cnt[u][it->first] == num[u])
{
ans[u]+=it->first;
}
}
}
}
int main()
{
scanf("%d",&n);
for(int i = 1;i<=n;i++)
scanf("%d",&c[i]);
for(int i = 1;i<=n-1;i++)
{
int u,v;
scanf("%d%d",&u,&v);
e[u].push_back(v);
e[v].push_back(u);
}
dfs(1,-1);

for(int i = 1;i<=n;i++)
printf("%lld%c",ans[i],i==n?'\n':' ');
}


E. Lomsat gelral
time limit per test
2 seconds
memory limit per test
256 megabytes
input
standard input
output
standard output

You are given a rooted tree with root in vertex 1. Each vertex is coloured in some colour.

Let's call colour c dominating in the subtree of vertex v if there are no other colours that appear in the subtree of vertex v more times than colour c. So it's possible that two or more colours will be dominating in the subtree of some vertex.

The subtree of vertex v is the vertex v and all other vertices that contains vertex v in each path to the root.

For each vertex v find the sum of all dominating colours in the subtree of vertex v.

Input

The first line contains integer n (1 ≤ n ≤ 105) — the number of vertices in the tree.

The second line contains n integers ci (1 ≤ ci ≤ n), ci — the colour of the i-th vertex.

Each of the next n - 1 lines contains two integers xj, yj (1 ≤ xj, yj ≤ n) — the edge of the tree. The first vertex is the root of the tree.

Output

Print n integers — the sums of dominating colours for each vertex.

Examples
input
4
1 2 3 4
1 2
2 3
2 4
output
10 9 3 4
input
15
1 2 3 1 2 3 3 1 1 3 2 2 1 2 3
1 2
1 3
1 4
1 14
1 15
2 5
2 6
2 7
3 8
3 9
3 10
4 11
4 12
4 13
output
6 5 4 3 2 3 3 1 1 3 2 2 1 2 3