题目大意
给你一棵树
让你支持子树染色，子树查询颜色个数，颜色数<=60, 节点数<=4e5
思路
因为颜色数很少，考虑状态压缩变成二进制
然后直接在dfs序上用线段树维护就可以了
//Author: dream_maker
#include<bits/stdc++.h>
using namespace std;
//----------------------------------------------
//typename
typedef long long ll;
//convenient for
#define fu(a, b, c) for (int a = b; a <= c; ++a)
#define fd(a, b, c) for (int a = b; a >= c; --a)
#define fv(a, b) for (int a = 0; a < (signed)b.size(); ++a)
//inf of different typename
const int INF_of_int = 1e9;
const ll INF_of_ll = 1e18;
//fast read and write
template <typename T>
void Read(T &x) {
bool w = 1;x = 0;
char c = getchar();
while (!isdigit(c) && c != '-') c = getchar();
if (c == '-') w = 0, c = getchar();
while (isdigit(c)) {
x = (x<<1) + (x<<3) + c -'0';
c = getchar();
}
if (!w) x = -x;
}
template <typename T>
void Write(T x) {
if (x < 0) {
putchar('-');
x = -x;
}
if (x > 9) Write(x / 10);
putchar(x % 10 + '0');
}
//----------------------------------------------
const int N = 4e5 + 10;
ll val[N << 2], tag[N << 2];
#define LD (t << 1)
#define RD (t << 1 | 1)
void pushup(int t) {
val[t] = val[LD] | val[RD];
}
void pushnow(int t, ll vl) {
val[t] = tag[t] = vl;
}
void pushdown(int t) {
if (tag[t]) {
pushnow(LD, tag[t]);
pushnow(RD, tag[t]);
tag[t] = 0;
}
}
void modify(int t, int l, int r, int ql, int qr, ll vl) {
if (ql <= l && r <= qr) {
pushnow(t, vl);
return;
}
pushdown(t);
int mid = (l + r) >> 1;
if (qr <= mid) modify(LD, l, mid, ql, qr, vl);
else if (ql > mid) modify(RD, mid + 1, r, ql, qr, vl);
else {
modify(LD, l, mid, ql, mid, vl);
modify(RD, mid + 1, r, mid + 1, qr, vl);
}
pushup(t);
}
ll query(int t, int l, int r, int ql, int qr) {
if (ql <= l && r <= qr) return val[t];
pushdown(t);
int mid = (l + r) >> 1;ll ans;
if (qr <= mid) ans = query(LD, l, mid, ql, qr);
else if (ql > mid) ans = query(RD, mid + 1, r, ql, qr);
else ans = query(LD, l, mid, ql, mid) | query(RD, mid + 1, r, mid + 1, qr);
pushup(t);
return ans;
}
struct Edge {
int v, nxt;
} E[N << 1];
int head[N], tot = 0;
int bg[N], ed[N], ind = 0;
int n, m, c[N];
void add(int u, int v) {
E[++tot] = (Edge) {v, head[u]};
head[u] = tot;
}
void dfs(int u, int fa) {
bg[u] = ++ind;
for (int i = head[u]; i; i = E[i].nxt) {
int v = E[i].v;
if (v == fa) continue;
dfs(v, u);
}
ed[u] = ind;
}
int bitcnt(ll a) {
int res = 0;
while (a) {
if (a & 1) ++res;
a >>= 1;
}
return res;
}
int main() {
//freopen("input.txt", "r", stdin);
Read(n), Read(m);
fu(i, 1, n) Read(c[i]);
fu(i, 2, n) {
int u, v;
Read(u), Read(v);
add(u, v);
add(v, u);
}
dfs(1, 0);
fu(i, 1, n) modify(1, 1, n, bg[i], bg[i], 1ll << c[i]);
while (m--) {
int op; Read(op);
switch(op) {
case 1: {
int x, col; Read(x), Read(col);
modify(1, 1, n, bg[x], ed[x], 1ll << col);
break;
}
case 2: {
int x; Read(x);
Write(bitcnt(query(1, 1, n, bg[x], ed[x])));
putchar('
');
break;
}
}
}
return 0;
}