/*
stuff i need to do:
- might need to make a permutation inverter
- compute preorder, make a translation table from tree index to preorder index
- compute subtree sizes; make sure to index by preorder
- compute BFS order, make a translation table from tree index to BFS index (and vice versa)
- segtree over BFS order
subroutine: binary search for the first node that's a subtree of some other node and is at some given depth
observation: dfs index is monotonic over a single level of a tree
first node invariant: l = set of all nodes such that dep[i] < dep_targ or dep[i] == dep_targ and dfs_order[i] < dfs_order[targ]
r is the first node
last node invariant: r = set of all nodes such that dep[i] > dep_targ or dep[i] == dep_targ and not within tree and sz[dfs_order[targ]] < dfs_order[i] - dfs_order[targ] + 1ll
*/
#pragma GCC optimize("O3", "unroll-loops")
#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef vector<ll> vll;
typedef vector<vll> vvll;
typedef vector<int> vi;
typedef vector<vi> vvi;
typedef vector<vvi> v3i;
typedef vector<v3i> v4i;
typedef vector<bool> vb;
typedef vector<vb> vvb;
typedef pair<int, int> pi;
typedef pair<ll, ll> pll;
typedef vector<pi> vpi;
typedef vector<pll> vpll;
#define INF(dt) numeric_limits<dt>::max()
#define NINF(dt) numeric_limits<dt>::min()
#define pb push_back
ll MOD = 1ll; // TODO set this to the correct value later on!
// struct Tree {
// Tree *lt, *rt;
// ll l, r, v;
// ll lazy;
// bool marked;
// Tree(ll a_l, ll a_r): lt(nullptr), rt(nullptr), l(a_l), r(a_r), lazy(1ll), marked(false) {};
// void push() {
// if(!marked) return;
// if(lt == nullptr) {
// marked = false;
// lazy = 1ll;
// return;
// }
// lt->lazy = (lt->lazy * lazy) % MOD;
// lt->v = (lt->v * lazy) % MOD;
// lt->marked = true;
// rt->lazy = (rt->lazy * lazy) % MOD;
// rt->v = (rt->v * lazy) % MOD;
// rt->marked = true;
// marked = false;
// lazy = 1ll;
// }
// void build(const vll& a) {
// if(l == r) {
// v = a[l];
// return;
// }
// ll m = (l + r) >> 1ll;
// lt = new Tree(l, m);
// rt = new Tree(m + 1ll, r);
// lt->build(a);
// rt->build(a);
// }
// void upd(ll ql, ll qr, ll qv) {
// if(ql > r || qr < l) return;
// push();
// if(ql == l && qr == r) {
// v = (v * qv) % MOD;
// lazy = (lazy * qv) % MOD;
// marked = true;
// return;
// }
// ll m = (l + r) >> 1ll;
// lt->upd(ql, min(qr, m), qv);
// rt->upd(max(ql, m + 1ll), qr, qv);
// }
// ll qry(ll i) {
// push();
// if(l == r) return v;
// return (i <= ((l + r) >> 1ll) ? lt : rt)->qry(i);
// }
// };
inline ll lt(ll i) {
return i << 1ll;
}
inline ll rt(ll i) {
return (i << 1ll) | 1ll;
}
// Tree(ll a_l, ll a_r): lt(nullptr), rt(nullptr), l(a_l), r(a_r), lazy(1ll), marked(false) {};
inline void tree_construct(ll n, ll i, ll a_l, ll a_r, vll& l, vll& r, vll& v, vll& lazy, vb& marked, vb& isempty) {
l[i] = a_l;
r[i] = a_r;
lazy[i] = 1ll;
marked[i] = false;
isempty[i] = false;
}
inline void push(ll n, ll i, vll& l, vll& r, vll& v, vll& lazy, vb& marked, vb& isempty) {
if(!marked[i]) return;
if(l[i] == r[i]) {
marked[i] = false;
lazy[i] = 1ll;
return;
}
lazy[lt(i)] = (lazy[lt(i)] * lazy[i]) % MOD;
v[lt(i)] = (v[lt(i)] * lazy[i]) % MOD;
marked[lt(i)] = true;
lazy[rt(i)] = (lazy[rt(i)] * lazy[i]) % MOD;
v[rt(i)] = (v[rt(i)] * lazy[i]) % MOD;
marked[rt(i)] = true;
marked[i] = false;
lazy[i] = 1ll;
}
inline void build(ll n, ll i, const vll& a, vll& l, vll& r, vll& v, vll& lazy, vb& marked, vb& isempty) {
if(l[i] == r[i]) {
v[i] = a[l[i]];
return;
}
ll m = (l[i] + r[i]) >> 1ll;
tree_construct(n, lt(i), l[i], m, l, r, v, lazy, marked, isempty);
tree_construct(n, rt(i), m + 1ll, r[i], l, r, v, lazy, marked, isempty);
build(n, lt(i), a, l, r, v, lazy, marked, isempty);
build(n, rt(i), a, l, r, v, lazy, marked, isempty);
}
inline void upd(ll n, ll i, ll ql, ll qr, ll qv, vll& l, vll& r, vll& v, vll& lazy, vb& marked, vb& isempty) {
if(ql > r[i] || qr < l[i]) return;
push(n, i, l, r, v, lazy, marked, isempty);
if(ql == l[i] && qr == r[i]) {
v[i] = (v[i] * qv) % MOD;
lazy[i] = (lazy[i] * qv) % MOD;
marked[i] = true;
return;
}
ll m = (l[i] + r[i]) >> 1ll;
upd(n, lt(i), ql, min(qr, m), qv, l, r, v, lazy, marked, isempty);
upd(n, rt(i), max(ql, m + 1ll), qr, qv, l, r, v, lazy, marked, isempty);
}
inline ll qry(ll n, ll i, ll qi, vll& l, vll& r, vll& v, vll& lazy, vb& marked, vb& isempty) {
push(n, i, l, r, v, lazy, marked, isempty);
if(l[i] == r[i]) return v[i];
return qry(n, (qi <= ((l[i] + r[i]) >> 1ll) ? lt(i) : rt(i)), qi, l, r, v, lazy, marked, isempty);
}
inline vll invert_perm(const vll& a) {
ll n = a.size();
vll res(n, 0ll);
for(ll i = 0ll; i < n; i++) {
res[a[i]] = i;
}
return res;
}
void compute_subtree_sizes(ll i, ll pr, vll& sz, const vll& dfs_order, const vvll& adj) {
sz[dfs_order[i]] = 1ll;
for(ll j : adj[i]) {
if(j == pr) continue;
compute_subtree_sizes(j, i, sz, dfs_order, adj);
sz[dfs_order[i]] += sz[dfs_order[j]];
}
}
bool is_in_subtree(ll i, ll pr, const vll& dfs_order, const vll& sz) {
return sz[dfs_order[pr]] >= dfs_order[i] - dfs_order[pr] + 1ll && dfs_order[i] >= dfs_order[pr];
}
void printv(const vll& a) {
for(ll v : a) cerr << v << " ";
cerr << endl;
}
/*
input: a target node (in original indexing) and a target depth
output: two node indices (in BFS order)
first node invariant: l = set of all nodes such that dep[i] < dep_targ or dep[i] == dep_targ and dfs_order[i] < dfs_order[targ]
r is the first node
last node invariant: r = set of all nodes such that dep[i] > dep_targ or dep[i] == dep_targ and not within tree and sz[dfs_order[targ]] < dfs_order[i] - dfs_order[targ] + 1ll
l is the last node
*/
pll bounding_inds(ll targ, ll dep_targ, const vll& dep, const vll& dfs_order, const vll& bfs_order, const vll& bfs_order_inv, const vll& sz) {
targ = bfs_order[targ];
ll dfs_order_targ = dfs_order[bfs_order_inv[targ]];
ll l = -1ll, r = dfs_order.size();
while(r - l > 1ll) {
ll m = (l + r) >> 1ll;
if(dep[bfs_order_inv[m]] < dep_targ || (dep[bfs_order_inv[m]] == dep_targ && dfs_order[bfs_order_inv[m]] < dfs_order_targ)) l = m;
else r = m;
}
ll fst = r;
l = -1ll, r = dfs_order.size();
ll targ_sz = sz[dfs_order_targ];
while(r - l > 1ll) {
ll m = (l + r) >> 1ll;
if(dep[bfs_order_inv[m]] > dep_targ || (dep[bfs_order_inv[m]] == dep_targ && targ_sz < dfs_order[bfs_order_inv[m]] - dfs_order_targ + 1ll)) r = m;
else l = m;
}
return {fst, l};
}
ll dfs_timer = 0ll;
void comp_dfs_order(ll i, ll pr, vll& dfs_order, const vvll& adj) {
dfs_order[i] = dfs_timer++;
for(ll j : adj[i]) {
if(j == pr) continue;
comp_dfs_order(j, i, dfs_order, adj);
}
}
int main() {
ios_base::sync_with_stdio(false); cin.tie(0); cout.tie(0);
// inputting graph information
ll n;
cin >> n >> MOD;
vvll adj(n, vll());
for(ll i = 0ll; i < n - 1ll; i++) {
ll a, b;
cin >> a >> b;
a--; b--;
adj[a].pb(b);
adj[b].pb(a);
}
// computing dfs order, parents, and depth
vll depths(n, -1ll);
vll dfs_order(n, 0ll);
stack<pll> s;
s.push({0ll, 0ll});
vb vis(n, false);
vll par(n, -1ll);
while(!s.empty()) {
auto [i, pr] = s.top();
s.pop();
if(vis[i]) continue;
vis[i] = true;
par[i] = pr;
depths[i] = depths[pr] + 1ll;
for(ll j : adj[i]) {
s.push({j, i});
}
}
comp_dfs_order(0ll, 0ll, dfs_order, adj);
// computing bfs order
vll bfs_order(n, 0ll);
queue<ll> q;
ll bfs_timer = 0ll;
for(ll i = 0ll; i < n; i++) vis[i] = false;
q.push(0ll);
while(!q.empty()) {
ll i = q.front();
q.pop();
if(vis[i]) continue;
vis[i] = true;
bfs_order[i] = bfs_timer++;
for(ll j : adj[i]) {
q.push(j);
}
}
vll bfs_order_inv = invert_perm(bfs_order);
// computing initial height array
vll h(n, 0ll);
vll h_bfs_ind(n, 0ll);
for(ll& v : h) cin >> v;
for(ll i = 0ll; i < n; i++) {
h_bfs_ind[bfs_order[i]] = h[i];
}
// building the segment tree
vll l(n << 2ll, 0ll);
vll r(n << 2ll, 0ll);
vll v(n << 2ll, 1ll);
vll lazy(n << 2ll, 1ll);
vb marked(n << 2ll, false);
vb isempty(n << 2ll, true);
tree_construct(n, 1ll, 0ll, n - 1ll, l, r, v, lazy, marked, isempty);
build(n, 1ll, h_bfs_ind, l, r, v, lazy, marked, isempty);
// computing subtree sizes
vll sz(n, 0ll);
compute_subtree_sizes(0ll, 0ll, sz, dfs_order, adj);
// testing stuff
// printv(dfs_order);
// printv(sz);
// printv(depths);
// printv(bfs_order);
// printv(bfs_order_inv);
// pll res = bounding_inds(13ll, 2ll, depths, dfs_order, bfs_order, bfs_order_inv, sz);
// cerr << res.first << " " << res.second << endl;
// answering queries
ll num_q;
cin >> num_q;
while(num_q--) {
int qtype;
cin >> qtype;
if(qtype == 1) {
// update
ll x, d, w;
cin >> x >> d >> w;
x--;
ll cur_targ = x;
ll cur_dep_targ = depths[cur_targ];
ll cur_dep_upd = cur_dep_targ + d;
while(cur_dep_upd >= cur_dep_targ && cur_dep_upd >= 0ll) {
auto [fst1, snd1] = bounding_inds(cur_targ, cur_dep_upd, depths, dfs_order, bfs_order, bfs_order_inv, sz);
if(fst1 <= snd1) {
upd(n, 1ll, fst1, snd1, w, l, r, v, lazy, marked, isempty);
}
cur_dep_upd--;
if(cur_dep_upd < cur_dep_targ || cur_dep_upd < 0ll) break;
auto [fst2, snd2] = bounding_inds(cur_targ, cur_dep_upd, depths, dfs_order, bfs_order, bfs_order_inv, sz);
if(fst2 <= snd2) {
upd(n, 1ll, fst2, snd2, w, l, r, v, lazy, marked, isempty);
}
cur_dep_upd--;
cur_dep_targ--;
cur_targ = par[cur_targ];
}
} else {
// query
ll x;
cin >> x;
x--;
cout << qry(n, 1ll, bfs_order[x], l, r, v, lazy, marked, isempty) << "\n";
}
}
cout << flush;
return 0;
}
# | Verdict | Execution time | Memory | Grader output |
---|
Fetching results... |
# | Verdict | Execution time | Memory | Grader output |
---|
Fetching results... |
# | Verdict | Execution time | Memory | Grader output |
---|
Fetching results... |
# | Verdict | Execution time | Memory | Grader output |
---|
Fetching results... |
# | Verdict | Execution time | Memory | Grader output |
---|
Fetching results... |
# | Verdict | Execution time | Memory | Grader output |
---|
Fetching results... |