洛谷P2664 树上游戏

https://www.luogu.org/problemnew/show/P2664

 #include<cstdio>
 #include<algorithm>
 #include<cstring>
 #include<vector>
 using namespace std;
 #define fi first
 #define se second
 #define mp make_pair
 #define pb push_back
 typedef long long ll;
 typedef unsigned long long ull;
 typedef pair<int,int> pii;
 struct E
 {
     int to,nxt;
 }e[];
 int f1[],ne;
 int sz[],a[];
 int n;
 ll t1[],t2[],s,ans[];
 void dfs1(int u,int fa)
 {
     sz[u]=;
     int v;
     ll t=t1[a[u]],z=t1[a[fa]];
     for(int k=f1[u];k;k=e[k].nxt)
         if(e[k].to!=fa)
         {
             v=e[k].to;
             dfs1(v,u);
             sz[u]+=sz[v];
         }
     t1[a[u]]=t+sz[u];
     t2[u]=t1[a[fa]]-z;
 }
 void dfs2(int u,int fa)
 {
     int v;ll ta;
     ans[u]=s;
     for(int k=f1[u];k;k=e[k].nxt)
         if(e[k].to!=fa)
         {
             v=e[k].to;
             ta=t1[a[v]];
             s+=n-t1[a[v]];
             t1[a[v]]=n;
             s+=t2[v]-sz[v];
             t1[a[u]]+=t2[v]-sz[v];
             dfs2(v,u);
             s+=ta-t1[a[v]];
             t1[a[v]]=ta;
             s-=t2[v]-sz[v];
             t1[a[u]]-=t2[v]-sz[v];
         }
 }
 int main()
 {
     int i,x,y;
     scanf("%d",&n);
     for(i=;i<=n;++i)
         scanf("%d",a+i);
     for(i=;i<n;++i)
     {
         scanf("%d%d",&x,&y);
         e[++ne].to=y;e[ne].nxt=f1[x];f1[x]=ne;
         e[++ne].to=x;e[ne].nxt=f1[y];f1[y]=ne;
     }
     dfs1(,);
     for(i=;i<=;++i)
         s+=t1[i];
     dfs2(,);
     for(i=;i<=n;++i)
         printf("%lld\n",ans[i]);
     return ;
 }