#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using ld = long double;
using db = double;
using str = string;
using pi = pair<int, int>;
using pl = pair<ll, ll>;
using pd = pair<db, db>;
using vi = vector<int>;
using vb = vector<bool>;
using vl = vector<ll>;
using vd = vector<db>;
using vs = vector<str>;
using vpi = vector<pi>;
using vpl = vector<pl>;
using vpd = vector<pd>;
#define mp make_pair
#define f first
#define s second
#define sz(x) (int)(x).size()
#define bg(x) begin(x)
#define all(x) bg(x), end(x)
#define sor(x) sort(all(x))
#define rsz resize
#define ins insert
#define ft front()
#define bk back()
#define pb push_back
#define pf push_front
#define lb lower_bound
#define ub upper_bound
#define FOR(i, a, b) for (int i = (a); i < (b); i++)
#define F0R(i, a) FOR(i, 0, a)
#define ROF(i, a, b) for (int i = (b) - 1; i >= (a); i--)
#define R0F(i, a) ROF(i, 0, a)
#define EACH(a, x) for (auto& a : x)
ll cdiv(ll a, ll b) { return a / b + ((a ^ b) > 0 && a % b); }
ll fdiv(ll a, ll b) { return a / b - ((a ^ b) < 0 && a % b); }
template<class T> bool ckmin(T& a, const T& b) { return b < a ? a = b, 1 : 0; }
template<class T> bool ckmax(T& a, const T& b) { return a < b ? a = b, 1 : 0; }
template<class T> void remDup(vector<T>& v) { sor(v); v.erase(unique(all(v)), v.end()); }
const int MOD = 1e9 + 7;
const int MXN = 2e5 + 10;
const int MXR = 25e3 + 10;
const ll INF = 1e18;
const int BLOCK = 450; int N, R, Q; int reg[MXN]; vi adj[MXN];
int timer = 1; int in[MXN], out[MXN]; vi S[MXR]; // Sorted list of {in, out}
vi allLarge; int ind[MXR]; int par[BLOCK][MXR], child[BLOCK][MXR];
void DFS(int X) {
in[X] = timer++; S[reg[X]].pb(X);
EACH(Y, adj[X]) DFS(Y); out[X] = timer - 1;
}
bool isAnc(int A, int B) { return in[A] <= in[B] && out[B] <= out[A]; }
// Get answer for (A, B), sz[A] > BLOCK, sz[B] <= BLOCK ~ O(N)
void genPar(int X, int large, int cnt) {
par[ind[large]][reg[X]] += cnt; int nCnt = cnt + (reg[X] == large);
EACH(Y, adj[X]) genPar(Y, large, nCnt);
}
// Get answer for (A, B), sz[A] <= BLOCK, sz[B] > BLOCK ~ O(N)
int genChild(int X, int large) {
int sub = (reg[X] == large); EACH(Y, adj[X]) sub += genChild(Y, large);
child[ind[large]][reg[X]] += sub; return sub;
}
// Get answer for (A, B), sz[A], sz[B] <= BLOCK ~ O(BLOCK)
int getAns(int A, int B) {
int L = 0, R = 0; int ans = 0; stack<int> anc;
while (L < sz(S[A]) || R < sz(S[B])) {
if (L < sz(S[A]) && (R == sz(S[B]) || in[S[A][L]] < in[S[B][R]])) {
while (!anc.empty() && !isAnc(anc.top(), S[A][L])) anc.pop(); anc.push(S[A][L]); L++;
}
else { while (!anc.empty() && !isAnc(anc.top(), S[B][R])) anc.pop(); ans += sz(anc); R++; }
}
return ans;
}
int main() {
ios_base::sync_with_stdio(false); cin.tie(0);
cin >> N >> R >> Q >> reg[1]; FOR(i, 2, N + 1) { int A; cin >> A >> reg[i]; adj[A].pb(i); }
DFS(1); int cnt = 0; FOR(i, 1, R + 1) if (sz(S[i]) > BLOCK) allLarge.pb(i), ind[i] = cnt++;
EACH(i, allLarge) { genPar(1, i, 0); genChild(1, i); }
F0R(i, Q) {
int A, B; cin >> A >> B;
if (sz(S[A]) <= BLOCK && sz(S[B]) <= BLOCK) { cout << getAns(A, B) << endl; continue; }
if (sz(S[A]) > BLOCK) cout << par[ind[A]][B] << endl; else cout << child[ind[B]][A] << endl;
}
}
Compilation message
regions.cpp: In function 'void DFS(int)':
regions.cpp:45:20: warning: this 'for' clause does not guard... [-Wmisleading-indentation]
45 | #define EACH(a, x) for (auto& a : x)
| ^~~
regions.cpp:69:5: note: in expansion of macro 'EACH'
69 | EACH(Y, adj[X]) DFS(Y); out[X] = timer - 1;
| ^~~~
regions.cpp:69:29: note: ...this statement, but the latter is misleadingly indented as if it were guarded by the 'for'
69 | EACH(Y, adj[X]) DFS(Y); out[X] = timer - 1;
| ^~~
regions.cpp: In function 'int getAns(int, int)':
regions.cpp:96:13: warning: this 'while' clause does not guard... [-Wmisleading-indentation]
96 | while (!anc.empty() && !isAnc(anc.top(), S[A][L])) anc.pop(); anc.push(S[A][L]); L++;
| ^~~~~
regions.cpp:96:75: note: ...this statement, but the latter is misleadingly indented as if it were guarded by the 'while'
96 | while (!anc.empty() && !isAnc(anc.top(), S[A][L])) anc.pop(); anc.push(S[A][L]); L++;
| ^~~
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
3 ms |
5576 KB |
Output is correct |
| 2 |
Correct |
4 ms |
5576 KB |
Output is correct |
| 3 |
Correct |
6 ms |
5576 KB |
Output is correct |
| 4 |
Correct |
6 ms |
5576 KB |
Output is correct |
| 5 |
Correct |
13 ms |
5576 KB |
Output is correct |
| 6 |
Correct |
30 ms |
5576 KB |
Output is correct |
| 7 |
Correct |
53 ms |
5576 KB |
Output is correct |
| 8 |
Correct |
45 ms |
5704 KB |
Output is correct |
| 9 |
Correct |
62 ms |
6088 KB |
Output is correct |
| 10 |
Correct |
82 ms |
6088 KB |
Output is correct |
| 11 |
Correct |
119 ms |
6344 KB |
Output is correct |
| 12 |
Correct |
177 ms |
6728 KB |
Output is correct |
| 13 |
Correct |
194 ms |
6472 KB |
Output is correct |
| 14 |
Correct |
243 ms |
7012 KB |
Output is correct |
| 15 |
Correct |
311 ms |
9408 KB |
Output is correct |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
1222 ms |
10244 KB |
Output is correct |
| 2 |
Correct |
1405 ms |
8832 KB |
Output is correct |
| 3 |
Correct |
2295 ms |
12348 KB |
Output is correct |
| 4 |
Correct |
343 ms |
6984 KB |
Output is correct |
| 5 |
Correct |
415 ms |
8564 KB |
Output is correct |
| 6 |
Correct |
885 ms |
11952 KB |
Output is correct |
| 7 |
Correct |
1613 ms |
10176 KB |
Output is correct |
| 8 |
Correct |
1309 ms |
23484 KB |
Output is correct |
| 9 |
Correct |
2517 ms |
13892 KB |
Output is correct |
| 10 |
Correct |
2980 ms |
30272 KB |
Output is correct |
| 11 |
Correct |
4107 ms |
13340 KB |
Output is correct |
| 12 |
Correct |
1215 ms |
15316 KB |
Output is correct |
| 13 |
Correct |
1733 ms |
15828 KB |
Output is correct |
| 14 |
Correct |
2724 ms |
18764 KB |
Output is correct |
| 15 |
Correct |
3217 ms |
20640 KB |
Output is correct |
| 16 |
Correct |
3156 ms |
27936 KB |
Output is correct |
| 17 |
Correct |
3156 ms |
29848 KB |
Output is correct |
