树状数组 || JZOI 1024. @szefany 的树

题面：无

题解：无

代码：

 #include<cstdio>
 #include<cstring>
 #include<iostream>
 #include<algorithm>
 using namespace std;
 const int maxn=(1e5)+;
 int N,T,u,v,num_edge,edge_head[maxn],lsh_cnt,belong[maxn],tr[maxn],Ans[maxn];
 //记住树状数组里不可以塞0
 //tr中的数会在回溯时删掉，所以不用清空tr
 struct Edge{int to,nx;}edge[maxn<<];
 inline void Add_edge(int from,int to){
     edge[++num_edge].nx=edge_head[from];
     edge[num_edge].to=to;
     edge_head[from]=num_edge;
     return;
 }
 struct Nd{int yw,w,id;}nd[maxn];
 inline bool cmp(const Nd&a,const Nd&b){return a.yw<b.yw;}
 inline void Add(int s,int x){
     for(int i=s;i>;i-=i&(-i))tr[i]+=x;
     return;
 }
 inline int Find(int s){
     int ans=;
     for(int i=s;i<=lsh_cnt;i+=i&(-i))ans+=tr[i];
     return ans;
 }
 inline void Dfs(int x,int f){
     for(int i=edge_head[x];i;i=edge[i].nx){
         int y=edge[i].to;
         if(y!=f){
             Add(nd[belong[x]].w,);
             Dfs(y,x);
             Add(nd[belong[x]].w,-);
         }
     }
     Ans[x]=Find(nd[belong[x]].w+);
     return;
 }
 int main(){
     scanf("%d",&T);
     while(T--){
         num_edge=lsh_cnt=;
         memset(edge_head,,sizeof(edge_head));
         scanf("%d",&N);
         for(int i=;i<N;i++){
             scanf("%d%d",&u,&v);
             Add_edge(u,v);
             Add_edge(v,u);
         }
         for(int i=;i<=N;i++){
             scanf("%d",&nd[i].yw);
             nd[i].id=i;
         }
         sort(nd+,nd+N+,cmp);
         nd[].w=++lsh_cnt;
         belong[nd[].id]=;
         for(int i=;i<=N;i++){
             if(nd[i].yw!=nd[i-].yw)lsh_cnt++;
             nd[i].w=lsh_cnt;
             belong[nd[i].id]=i;
         }
         Dfs(,);
         for(int i=;i<=N;i++)printf("%d\n",Ans[i]);
     }
     return ;
 }

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By:AlenaNuna