# | Time | Username | Problem | Language | Result | Execution time | Memory |
---|---|---|---|---|---|---|---|
1228845 | CrabCNH | Regions (IOI09_regions) | C++20 | 0 ms | 0 KiB |
#include <bits/stdc++.h>
#define task "BriantheCrab"
#define pii pair <int, int>
#define fi first
#define se second
#define szf sizeof
#define sz(s) (int)((s).size())
#define all(v) (v).begin(), (v).end()
typedef long long ll;
typedef unsigned long long ull;
typedef long double ld;
using namespace std;
template <class T> void minimize (T &t, T f) {if (t > f) t = f;}
template <class T> void maximize (T &t, T f) {if (t < f) t = f;}
const int maxN = 2e5 + 5;
const int inf = 1e18 + 7;
const int mod = 1e9 + 7;
const int base = 450;
// khong tu code thi khong kha len duoc dau
int n, R, q;
int a[maxN];
vector <int> adj[maxN];
int gr[maxN];
int tIn[maxN], tOut[maxN];
vector <int> cc[maxN], tcc[maxN];
int timer = 0;
int par[maxN], sum[maxN];
vector <int> res[maxN];
void dfsPre (int u, int p) {
tIn[u] = ++timer;
cc[gr[u]].push_back (u);
for (auto v : adj[u]) {
if (v == p) {
continue;
}
dfsPre (v, u);
}
tOut[u] = timer;
}
void dfs (int u, int p, int curS, int r) {
for (auto v : adj[u]) {
if (v == p) {
continue;
}
sum[gr[v]] += curS;
//cout << "gay " << v << ' ' << gr[v] << ' ' << curS << '\n';
dfs (v, u, curS + (gr[v] == r), r);
}
}
void solve () {
cin >> n >> R >> q;
cin >> gr[1];
par[1] = 0;
for (int i = 2; i <= n; i ++) {
int p;
cin >> p >> gr[i];
par[i] = p;
adj[p].push_back (i);
adj[i].push_back (p);
//cout << i << ' ' << p << '\n';
}
dfsPre (1, 1);
for (int r = 1; r <= R; r++){
tcc[r].reserve (cc[r].size());
for (int u : cc[r]){
tcc[r].push_back (tIn[u]);
}
sort(tcc[r].begin(), tcc[r].end());
}
for (int i = 1; i <= q; i ++) {
int r1, r2;
cin >> r1 >> r2;
if (sz (tcc[r1]) < base) {
int res = 0;
for (auto u : cc[r1]) {
int lPos = lower_bound (all (tcc[r2]), tIn[u]) - tcc[r2].begin ();
int rPos = upper_bound (all (tcc[r2]), tOut[u]) - tcc[r2].begin ();
res += (rPos - lPos);
//cout << r << ' ' << l << '\n';
}
cout << res << '\n';
}
else {
if (res[r1].empty ()) {
int rt = 0;
dfs (1, 1, gr[1] == r1, r1);
for (int i = 1; i <= R; i ++) {
res[r1].push_back (sum[i]);
//cout << sum[i] << ' ';
sum[i] = 0;
}
}
cout << res[r1][r2 - 1] << '\n';
cout << flush ();
}
}
return;
}
signed main () {
cin.tie (nullptr) -> sync_with_stdio (false);
if (fopen (task".inp", "r")) {
freopen (task".inp", "r", stdin);
freopen (task".out", "w", stdout);
}
int t = 1;
//cin >> t;
while (t --) {
solve ();
}
return 0;
}
// thfv