#include <bits/stdc++.h>
using namespace std;
using vi = vector<int>;
using vvi = vector<vi>;
const int BIG = 500;
vi r, tin, tout, big_id;
vvi adj, tins, touts, by_r;
vector<vector<long long>> dp;
int timer;
void euler(int u, int p) {
tin[u] = timer++;
tins[r[u]].push_back(tin[u]);
for (int v : adj[u]) {
if (v != p) euler(v, u);
}
tout[u] = timer++;
touts[r[u]].push_back(tout[u]);
}
int count_in_range(const vi& v, int l, int r) {
if (v.empty()) return 0;
int i = upper_bound(v.begin(), v.end(), r) - v.begin();
int j = upper_bound(v.begin(), v.end(), l) - v.begin();
// cerr << "$$" << 1+rg << " " << l << " " << r << " " << j << " " << i << " " << i - j << endl;
return i - j;
}
void precompute(int rg, int p, int u) {
// cerr << "%" << 1+rg << " " << 1+u << endl;
int rid = big_id[rg];
cerr << 1+rg << " RID " << rid << " " << u << endl;
dp[rid][u] = (r[u] == rg);
for (int v : adj[u]) {
if (v != p) {
precompute(rg, u, v);
dp[rid][u] += dp[rid][v];
}
}
}
int main() {
ios::sync_with_stdio(0);
cin.tie(0);
int N, R, Q;
cin >> N >> R >> Q;
r = tin = tout = vi(N);
big_id = vi(R);
adj = vvi(N);
tins = touts = by_r = vvi(R);
vi p(N, -1);
cin >> r[0]; --r[0];
by_r[r[0]].push_back(0);
for (int i = 1; i < N; ++i) {
cin >> p[i] >> r[i]; --p[i], --r[i];
by_r[r[i]].push_back(i);
adj[i].push_back(p[i]);
adj[p[i]].push_back(i);
}
int bigs = 0;
for (int rg = 0; rg < R; ++rg) {
if (by_r[rg].size() >= BIG) big_id[rg] = bigs++;
}
dp = vector<vector<long long>>(bigs, vector<long long>(N));
for (int rg = 0; rg < R; ++rg) {
if (by_r[rg].size() >= BIG) precompute(rg, 0, 0);
}
timer = 1;
euler(0, 0);
// for (int x : tins[3-1]) cerr << x << " "; cerr << endl;
// for (int i = 0; i < N; ++i) {
// cerr << 1+i << " " << 1+r[i] << " " << tin[i] << " " << tout[i] << endl;
// }
// for (int i = 1; i < N; ++i) {
// cerr << 1+i << "(" << 1+r[i] << ")"
// << " " << 1+p[i] << "(" << 1+r[p[i]] << ")" << endl;
// }
// cerr << endl << endl;
map<pair<int,int>,long long> mem;
while (Q--) {
int r1, r2;
cin >> r1 >> r2; --r1, --r2;
// cerr << 1+r1 << " " << 1+r2 << endl;
if (by_r[r1].size() < BIG and by_r[r2].size() >= BIG) { // r1 small r2 big
long long cnt = 0;
int rid = big_id[r2];
for (int u : by_r[r1]) {
cnt += dp[rid][u];
}
cout << cnt << endl;
}
else {
if (not mem.count({r1,r2})) {
long long cnt = 0;
for (int u : by_r[r2]) {
cnt += count_in_range(tins[r1], 0, tin[u])
- count_in_range(touts[r1], 0, tin[u]);
}
mem[{r1,r2}] = cnt;
}
cout << mem[{r1,r2}] << endl;
}
}
}
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
1 ms |
320 KB |
Output is correct |
2 |
Correct |
1 ms |
208 KB |
Output is correct |
3 |
Correct |
2 ms |
208 KB |
Output is correct |
4 |
Correct |
4 ms |
336 KB |
Output is correct |
5 |
Correct |
6 ms |
392 KB |
Output is correct |
6 |
Correct |
12 ms |
484 KB |
Output is correct |
7 |
Correct |
24 ms |
528 KB |
Output is correct |
8 |
Correct |
28 ms |
712 KB |
Output is correct |
9 |
Correct |
27 ms |
1356 KB |
Output is correct |
10 |
Correct |
83 ms |
1844 KB |
Output is correct |
11 |
Correct |
124 ms |
2200 KB |
Output is correct |
12 |
Correct |
149 ms |
3032 KB |
Output is correct |
13 |
Correct |
155 ms |
3404 KB |
Output is correct |
14 |
Correct |
245 ms |
3780 KB |
Output is correct |
15 |
Correct |
279 ms |
7532 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
6359 ms |
30576 KB |
Output is correct |
2 |
Correct |
7364 ms |
33600 KB |
Output is correct |
3 |
Correct |
7252 ms |
35716 KB |
Output is correct |
4 |
Correct |
283 ms |
5168 KB |
Output is correct |
5 |
Correct |
351 ms |
7716 KB |
Output is correct |
6 |
Correct |
6309 ms |
32724 KB |
Output is correct |
7 |
Correct |
681 ms |
9308 KB |
Output is correct |
8 |
Correct |
2989 ms |
27364 KB |
Output is correct |
9 |
Correct |
2578 ms |
25212 KB |
Output is correct |
10 |
Correct |
3909 ms |
34124 KB |
Output is correct |
11 |
Correct |
4552 ms |
33332 KB |
Output is correct |
12 |
Correct |
3400 ms |
32244 KB |
Output is correct |
13 |
Correct |
4257 ms |
35420 KB |
Output is correct |
14 |
Execution timed out |
8096 ms |
75748 KB |
Time limit exceeded |
15 |
Correct |
5656 ms |
46436 KB |
Output is correct |
16 |
Correct |
5390 ms |
55248 KB |
Output is correct |
17 |
Execution timed out |
8096 ms |
88428 KB |
Time limit exceeded |