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#include<iostream>
#include<cstdio>
#include<cmath>
#include<cstring>
#include<algorithm>
using namespace std;
const int N = 1e5 + 15;
inline int ()
{
int x = 0; char ch = getchar();
while(ch < '0' || ch > '9') ch = getchar();
while(ch >= '0' && ch <= '9') {
x = x * 10 + (ch - '0');
ch = getchar();
}
return x;
}
int n, m, size[N], son[N], li[N], tr[N], retr[N], fa[N], deep[N], col[N], w[N], tot;
struct Edge{
int to, next;
}E[N * 2]; int head[N], ecnt = 1;
inline void add(int a, int b)
{
E[++ecnt] = (Edge) {b, head[a]}; head[a] = ecnt;
E[++ecnt] = (Edge) {a, head[b]}; head[b] = ecnt;
}
#define FOR(x) for(int e = head[x]; e; e = E[e].next)
struct seg_t {
int l, r, lc, rc, col, sum;
}a[N * 4];
struct co{
int l, r, sum;
co() {
l = r = sum = 0;
}
};
inline void dfs1(int x, int f, int de)
{
fa[x] = f, deep[x] = de;
FOR(x) {
int go = E[e].to;
if(go == fa[x]) continue;
dfs1(go, x, de + 1);
size[x] += size[go];
if(size[go] > size[son[x]] || son[x] == x) {
son[x] = go;
}
}
return ;
}
inline void dfs2(int x, int f)
{
li[x] = f, tr[x] = ++tot, retr[tr[x]] = x;
if(son[x] == x) return ;
if(son[x] != x)
dfs2(son[x], f);
FOR(x) {
int go = E[e].to;
if(go == fa[x]) continue;
if(go != son[x])
dfs2(go, go);
}
return ;
}
inline void up(int k)
{
a[k].lc = a[k << 1].lc; a[k].rc = a[(k << 1) + 1].rc;
a[k].sum = a[k << 1].sum + a[(k << 1) + 1].sum;
if(a[(k << 1) + 1].lc == a[k << 1].rc) a[k].sum--;
return ;
}
inline void build(int l, int r, int k)
{
a[k].l = l, a[k].r = r; a[k].lc = a[k].rc = a[k].col = -1;
if(l == r) {
a[k].lc = a[k].rc = w[retr[l]];
a[k].sum = 1;
return ;
}
int mid = (l + r) >> 1;
build(l, mid, k << 1); build(mid + 1, r, (k << 1) + 1);
up(k);
return ;
}
inline void chuan(int k)
{
if(a[k].l == a[k].r) return ;
a[k << 1].col = a[(k << 1) + 1].col = a[k].col;
a[k << 1].lc = a[k << 1].rc = a[k << 1].col;
a[k << 1].sum = 1;
a[(k << 1) + 1].lc = a[(k << 1) + 1].rc = a[(k << 1) + 1].col;
a[(k << 1) + 1].sum = 1;
a[k].col = -1;
return ;
}
inline void cov(int l, int r, int k, int v)
{
if(a[k].l >= l && a[k].r <= r)
{
a[k].lc = a[k].rc = v;
a[k].col = v;
a[k].sum = 1;
return ;
}
if(a[k].col != -1) chuan(k);
int mid = (a[k].l + a[k].r) >> 1;
if(l <= mid) cov(l, r, k << 1, v);
if(r > mid) cov(l, r, (k << 1) + 1, v);
up(k);
}
inline co QQ(int l, int r, int k)
{
if(a[k].l >= l && a[k].r <= r)
{
if(a[k].col != -1) chuan(k);
co c;
c.l = a[k].lc, c.r = a[k].rc, c.sum = a[k].sum;
return c;
}
if(a[k].col != -1) chuan(k);
int mid = (a[k].l + a[k].r) >> 1;
co an1, an2;
if(l <= mid) an1 = QQ(l, r, k << 1);
if(r > mid) an2 = QQ(l, r, (k << 1) + 1);
if(an1.sum == 0) return an2;
if(an2.sum == 0) return an1;
an1.sum += an2.sum;
if(an1.r == an2.l) an1.sum--;
an1.r = an2.r;
up(k);
return an1;
}
inline void cover(int u, int v, int f)
{
int uu = u, vv = v;
int no1 = li[uu], no2 = li[vv];
while(no1 != no2) {
if(deep[no1] < deep[no2]) swap(uu, vv), swap(no1, no2);
cov(tr[no1], tr[uu], 1, f);
uu = fa[no1], no1 = li[uu];
}
if(tr[uu] > tr[vv]) cov(tr[vv], tr[uu], 1, f);
else cov(tr[uu], tr[vv], 1, f);
return ;
}
inline int que(int u, int v)
{
int uu = u, vv = v;
co aa, ba, t;
int no1 = li[uu], no2 = li[vv];
while(no1 != no2) {
if(deep[no1] < deep[no2]){
t = aa; aa = ba; ba = t;
swap(uu, vv); swap(no1, no2);
}
t = QQ(tr[no1], tr[uu], 1);
aa.sum += t.sum;
if(aa.l == t.r) aa.sum--;
aa.l = t.l;
uu = fa[no1], no1 = li[uu];
}
if(deep[uu] > deep[vv]) {
swap(uu, vv);
t = aa; aa = ba; ba = t;
}
t = QQ(tr[uu], tr[vv], 1);
t.sum += aa.sum; if(t.l == aa.l) t.sum--;
t.sum += ba.sum; if(t.r == ba.l) t.sum--;
return t.sum;
}
int main()
{
n = read(), m = read();
for(int i = 1; i <= n; ++i)
{
w[i] = read();
size[i] = 1; fa[i] = i; son[i] = i;
}
for(int i = 1; i < n; ++i)
{
int u = read(), v = read();
add(u, v);
}
dfs1(1, 1, 1);
dfs2(1, 1);
build(1, n, 1); char s[2];
for(int i = 1; i <= m; ++i)
{
scanf("%s", s);
int u = read(), v = read();
if(s[0] == 'Q') {
int ans = que(u ,v);
printf("%dn", ans);
}
if(s[0] == 'C') {
int r = read();
cover(u, v, r);
}
}
return 0;
}
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