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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;
vector <int> g[N];
int n, m, d[N], p[N], sz[N];
int stmp, dfn[N], son[N], top[N];
struct Data { int lc, rc, s; };
const Data e = (Data){ 0, 0, -1 };
Data operator ~ (Data _) { swap(_.lc, _.rc); return _; }
struct Node { int l, r, tag; Data k; } tr[N << 2];
Data pushup (Data l, Data r)
{
if (!~l.s) return r;
if (!~r.s) return l;
return (Data){ l.lc, r.rc, l.s + r.s + (l.rc == r.lc) };
}
void cover (int x, int c)
{
tr[x].k.lc = tr[x].k.rc = c;
tr[x].k.s = tr[x].r - tr[x].l;
tr[x].tag = c;
}
void pushdown (int x)
{
if (!~tr[x].tag) return;
cover(x << 1, tr[x].tag), cover(x << 1 | 1, tr[x].tag);
tr[x].tag = -1;
}
void build (int l = 1, int r = n, int x = 1)
{
tr[x].l = l, tr[x].r = r, tr[x].tag = -1;
if (l == r) return void(tr[x].k = (Data){ -l, -l, 0 });
int mid = l + r >> 1;
build(l, mid, x << 1), build(mid + 1, r, x << 1 | 1);
tr[x].k = pushup(tr[x << 1].k, tr[x << 1 | 1].k);
}
void modify (int l, int r, int c, int x = 1)
{
if (l > tr[x].r || tr[x].l > r) return;
if (tr[x].l >= l && tr[x].r <= r) return cover(x, c);
pushdown(x);
modify(l, r, c, x << 1), modify(l, r, c, x << 1 | 1);
tr[x].k = pushup(tr[x << 1].k, tr[x << 1 | 1].k);
}
Data query (int l, int r, int x = 1)
{
if (l > tr[x].r || tr[x].l > r) return e;
if (tr[x].l >= l && tr[x].r <= r) return tr[x].k;
pushdown(x);
return pushup(query(l, r, x << 1), query(l, r, x << 1 | 1));
}
void dfs1 (int u)
{
sz[u] = 1, son[u] = 0;
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;
if (!son[u]) return;
dfs2(son[u], t);
for (int v : g[u]) if (v ^ p[u] && v ^ son[u])
dfs2(v, v);
}
void ModifyPath (int a, int b, int c)
{
while (top[a] ^ top[b])
{
if (d[top[a]] < d[top[b]]) swap(a, b);
modify(dfn[top[a]], dfn[a], c);
a = p[top[a]];
}
if (d[a] > d[b]) swap(a, b);
modify(dfn[a], dfn[b], c);
}
Data QueryPath (int a, int b)
{
Data da = e, db = e;
while (top[a] ^ top[b])
{
if (d[top[a]] < d[top[b]]) swap(a, b), swap(da, db);
da = pushup(query(dfn[top[a]], dfn[a]), da);
a = p[top[a]];
}
if (d[a] > d[b]) swap(a, b), swap(da, db);
return pushup(pushup(~da, query(dfn[a], dfn[b])), db);
}
int main ()
{
int T; read(T);
while (T--)
{
read(n, m);
for (int i = 1; i <= n; ++i) g[i].clear();
for (int i = 1, a, b; i < n; ++i)
read(a, b), g[a].pb(b), g[b].pb(a);
stmp = 0; dfs1(1), dfs2(1, 1); build();
for (int i = 1, op, a, b; i <= m; ++i)
{
read(op, a, b);
if (op == 1) ModifyPath(a, b, i);
else if (op == 2) write(QueryPath(a, b).s), puts("");
}
}
return 0;
}
|