【hdu4366】dfs序线段树

 #include <bits/stdc++.h>
 #define ll long long
 #define lson l, m, rt<<1
 #define rson m+1, r, rt<<1|1
 using namespace std;
 const int N = 5e4+;

 vector<int> ve[N];
 int b[N], c[N], tot;
 int l[N], r[N], ans[N];
 void dfs(int fa, int x){
     tot++;
     l[x] = tot;
     for(int i = ; i < ve[x].size(); i++){
         int y = ve[x][i];
         if(y == fa) continue ;
         dfs(x, y);
     }
     r[x] = tot;
 }

 struct Node{
     int b, pos;
     Node(){}
     Node(int b, int pos): b(b), pos(pos){}
     bool operator <(const Node& a) const{
         return b < a.b;
     }
 };
 Node T[N<<];

 void pushup(int rt){
     T[rt] = max(T[rt<<], T[rt<<|]);
 }
 void build(int l, int r, int rt){
     T[rt].b = T[rt].pos = -;
     if(l == r) return ;
     int m = l+r >> ;
     build(lson);
     build(rson);
 }
 void update(int pos, Node x, int l, int r, int rt){
     if(pos == l&&r == pos){
         T[rt] = x;
         return ;
     }
     int m = l+r >> ;
     if(pos <= m) update(pos, x, lson);
     else update(pos, x, rson);
     pushup(rt);
 }
 Node query(int L, int R, int l, int r, int rt){
     if(L <= l&&r <= R)
         return T[rt];
     int m = l+r >> ;
     Node ret = Node(-, -);
     if(L <= m) ret = max(ret, query(L, R, lson));
     if(R > m) ret = max(ret, query(L, R, rson));
     return ret;
 }

 struct p{
     int b, c, id, kth;
     p(){}
     p(int b, int c, int id, int kth):b(b), c(c), id(id), kth(kth){}
     bool operator < (const p& a) const{
         return c != a.c? c > a.c: kth < a.kth;
     }
 };
 p pp[N];

 int main(){
     int t; scanf("%d", &t);
     while(t--){
         int n, m, x;
         scanf("%d%d", &n, &m);
         for(int i = ; i < n; i++) ve[i].clear();
         b[] = c[] = -;
         for(int i = ; i < n; i++){
             scanf("%d%d%d", &x, b+i, c+i);
             ve[x].push_back(i);
         }

         tot = ;
         dfs(-, );
         for(int i = ; i < n; i++)
             pp[i] = p(b[i], c[i], i, l[i]);
         sort(pp+, pp+n);
         build(, n, );
         for(int i = ; i < n; i++){
             int j = pp[i].id;
             int L = l[j]+, R = r[j];
             if(L > R) ans[j] = -;
             else
                 ans[j] = query(L, R, , tot, ).pos;
             update(l[j], Node(pp[i].b, pp[i].id), , tot, );
         }
         while(m--){
             scanf("%d", &x);
             printf("%d\n", ans[x]);
         }
     }
     return ;
 }