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| #include <cstdio>
#include <vector>
#define pb push_back
using namespace std;
template <class Type>
void read (Type &x)
{
char c;
bool flag = false;
while ((c = getchar()) < '0' || c > '9')
c == '-' && (flag = true);
x = c - '0';
while ((c = getchar()) >= '0' && c <= '9')
x = (x << 1) + (x << 3) + c - '0';
flag && (x = ~x + 1);
}
template <class Type, class ...rest>
void read (Type &x, rest &...y) { read(x), read(y...); }
template <class Type>
void write (Type x)
{
x < 0 && (putchar('-'), x = ~x + 1);
x > 9 && (write(x / 10), 0);
putchar('0' + x % 10);
}
const int N = 1e5 + 10, M = 30;
int n, q, w[N], d[N], p[N], sz[N];
int stmp, dfn[N], son[N], top[N];
vector <int> g[N];
int idx, rt[2][N];
struct Trie { int s[2], c; } tr[2 * N * (M + 1)];
void insert (int &x, int k, int t = M - 1)
{
tr[++idx] = tr[x]; x = idx;
++tr[x].c;
if (!~t) return;
insert(tr[x].s[k >> t & 1], k, t - 1);
}
int query (vector <int> &x, vector <int> &y, int k, int t = M - 1)
{
if (!~t) return 0;
int c = k >> t & 1, s = 0;
for (int i : x) s -= tr[tr[i].s[c ^ 1]].c;
for (int i : y) s += tr[tr[i].s[c ^ 1]].c;
if (s > 0)
{
for (int &i : x) i = tr[i].s[c ^ 1];
for (int &i : y) i = tr[i].s[c ^ 1];
return query(x, y, k, t - 1) | 1 << t;
}
else
{
for (int &i : x) i = tr[i].s[c];
for (int &i : y) i = tr[i].s[c];
return query(x, y, k, t - 1);
}
}
void dfs1 (int u)
{
sz[u] = 1;
for (int v : g[u]) if (v ^ p[u])
{
p[v] = u;
d[v] = d[u] + 1;
dfs1(v);
sz[u] += sz[v];
if (sz[v] > sz[son[u]]) son[u] = v;
}
}
void dfs2 (int u, int t)
{
top[u] = t;
dfn[u] = ++stmp;
insert(rt[0][stmp] = rt[0][stmp - 1], w[u]);
insert(rt[1][u] = rt[1][p[u]], w[u]);
if (!son[u]) return;
dfs2(son[u], t);
for (int v : g[u]) if (v ^ p[u] && v ^ son[u])
dfs2(v, v);
}
int lca (int a, int b)
{
while (top[a] ^ top[b])
{
if (d[top[a]] < d[top[b]]) swap(a, b);
a = p[top[a]];
}
if (d[a] > d[b]) swap(a, b);
return a;
}
int main ()
{
read(n, q);
for (int i = 1; i <= n; ++i) read(w[i]);
for (int i = 1, a, b; i < n; ++i)
read(a, b), g[a].pb(b), g[b].pb(a);
insert(rt[0][0], 0), insert(rt[1][0], 0);
dfs1(1), dfs2(1, 1);
for (int op; q; --q)
{
read(op);
if (op == 1)
{
int t, k; read(t, k);
vector <int> a {rt[0][dfn[t] - 1] }, b { rt[0][dfn[t] + sz[t] - 1] };
write(query(a, b, k)), puts("");
}
else if (op == 2)
{
int x, y, k; read(x, y, k);
int t = lca(x, y);
vector <int> a { rt[1][t], rt[1][p[t]] }, b { rt[1][x], rt[1][y] };
write(query(a, b, k)), puts("");
}
}
return 0;
}
|