题面
Sol
我也不知道哪里来的题目哪里来的\(OJ\)
子树变成\(DFS\)序后就是裸的树套树
# include <bits/stdc++.h>
# define RG register
# define IL inline
# define Fill(a, b) memset(a, b, sizeof(a))
using namespace std;
const int _(3e4 + 1);
typedef long long ll;
IL int Input(){
RG int x = 0, z = 1; RG char c = getchar();
for(; c < '0' || c > '9'; c = getchar()) z = c == '-' ? -1 : 1;
for(; c >= '0' && c <= '9'; c = getchar()) x = (x << 1) + (x << 3) + (c ^ 48);
return x * z;
}
int w[_], n, tmp1[20], tmp2[20], first[_], cnt, L[_], R[_], idx, num, rt[_];
struct Edge{
int to, next;
} edge[_ << 1];
struct Segment{
int ls, rs, sz;
} T[_ * 200];
IL void Add_Graph(RG int u, RG int v){
edge[cnt] = (Edge){v, first[u]}, first[u] = cnt++;
}
IL void Dfs(RG int u, RG int ff){
L[u] = ++idx;
for(RG int e = first[u]; e != -1; e = edge[e].next)
if(edge[e].to != ff) Dfs(edge[e].to, u);
R[u] = idx;
}
IL void Modify(RG int &x, RG int l, RG int r, RG int p, RG int v){
if(!x) x = ++num; T[x].sz += v;
if(l == r) return;
RG int mid = (l + r) >> 1;
if(p <= mid) Modify(T[x].ls, l, mid, p, v);
else Modify(T[x].rs, mid + 1, r, p, v);
}
IL void Add(RG int x, RG int v, RG int d){
for(; x <= n; x += x & -x) Modify(rt[x], 1, 10000, v, d);
}
IL int QueryKth(RG int l, RG int r, RG int k){
if(l == r) return l;
RG int sum = 0, mid = (l + r) >> 1;
for(RG int i = 1; i <= tmp1[0]; ++i) sum -= T[T[tmp1[i]].ls].sz;
for(RG int i = 1; i <= tmp2[0]; ++i) sum += T[T[tmp2[i]].ls].sz;
if(k <= sum){
for(RG int i = 1; i <= tmp1[0]; ++i) tmp1[i] = T[tmp1[i]].ls;
for(RG int i = 1; i <= tmp2[0]; ++i) tmp2[i] = T[tmp2[i]].ls;
return QueryKth(l, mid, k);
}
for(RG int i = 1; i <= tmp1[0]; ++i) tmp1[i] = T[tmp1[i]].rs;
for(RG int i = 1; i <= tmp2[0]; ++i) tmp2[i] = T[tmp2[i]].rs;
return QueryKth(mid + 1, r, k - sum);
}
IL int Kth(RG int l, RG int r, RG int k){
tmp1[0] = tmp2[0] = 0;
for(RG int i = l - 1; i; i -= i & -i) tmp1[++tmp1[0]] = rt[i];
for(RG int i = r; i; i -= i & -i) tmp2[++tmp2[0]] = rt[i];
return QueryKth(1, 10000, k);
}
IL int QuerySum(RG int x, RG int l, RG int r, RG int ql, RG int qr){
if(!x) return 0;
if(ql <= l && qr >= r) return T[x].sz;
RG int mid = (l + r) >> 1, ret = 0;
if(ql <= mid) ret = QuerySum(T[x].ls, l, mid, ql, qr);
if(qr > mid) ret += QuerySum(T[x].rs, mid + 1, r, ql, qr);
return ret;
}
IL int Sum(RG int x, RG int l, RG int r){
RG int ret = 0;
for(; x; x -= x & -x) ret += QuerySum(rt[x], 1, 10000, l, r);
return ret;
}
int main(RG int argc, RG char* argv[]){
n = Input();
for(RG int i = 1; i <= n; ++i) first[i] = -1, w[i] = Input();
for(RG int i = 1; i < n; ++i){
RG int u = Input(), v = Input();
Add_Graph(u, v), Add_Graph(v, u);
}
Dfs(1, 0);
for(RG int i = 1; i <= n; ++i) Add(L[i], w[i], 1);
for(RG int q = Input(); q; --q){
RG int op = Input(), u = Input(), x = Input(), y;
if(op == 1) printf("%d\n", Kth(L[u], R[u], x));
else if(op == 2) y = Input(), printf("%d\n", Sum(R[u], x, y) - Sum(L[u] - 1, x, y));
else Add(L[u], w[u], -1), w[u] = x, Add(L[u], w[u], 1);
}
return 0;
}