#include <bits/stdc++.h>
using namespace std;
const int nax = 2e5 + 5;
int region[nax];
vector<int> edges[nax], positions[nax];
int tin[nax], tout[nax], who[nax];
int timer = 0;
unordered_map<int, int> mp[25005];
void dfs (int u, int p) {
tin[u] = ++timer;
who[timer] = u;
positions[region[u]].push_back(timer);
for (int v : edges[u]) {
if (v != p) {
dfs (v, u);
}
}
tout[u] = timer;
}
void solve() {
int n, r, q;
cin >> n >> r >> q;
cin >> region[1];
for (int i = 2; i <= n; ++i) {
int p;
cin >> p >> region[i];
edges[i].push_back(p);
edges[p].push_back(i);
}
dfs (1, 0);
const int B = sqrt(n);
for (int reg = 1; reg <= r; ++reg) {
if (positions[reg].size() >= B) {
vector<int> pref(n + 2);
for (int i = 1; i <= n; ++i) {
if (region[who[i]] == reg) {
pref[i + 1]++;
pref[tout[who[i]] + 1]--;
}
}
for (int i = 1; i <= n; ++i) {
pref[i] += pref[i - 1];
mp[reg][region[who[i]]] += pref[i];
}
}
}
while (q--) {
int reg1, reg2;
cin >> reg1 >> reg2;
if (positions[reg1].size() >= B) {
cout << mp[reg1][reg2] << endl;
} else {
int ans = 0;
for (int i : positions[reg1]) {
if (region[who[i]] == reg1) {
auto it1 = upper_bound(positions[reg2].begin(), positions[reg2].end(), tout[who[i]]) - positions[reg2].begin();
auto it2 = lower_bound(positions[reg2].begin(), positions[reg2].end(), i) - positions[reg2].begin();
if (it1 != 0) {
ans += it1 - it2;
}
}
}
cout << ans << endl;
}
}
}
int main()
{
ios_base::sync_with_stdio(false);
cin.tie(0);
cout.tie(0);
solve();
}
Compilation message
regions.cpp: In function 'void solve()':
regions.cpp:38:35: warning: comparison of integer expressions of different signedness: 'std::vector<int>::size_type' {aka 'long unsigned int'} and 'const int' [-Wsign-compare]
38 | if (positions[reg].size() >= B) {
| ~~~~~~~~~~~~~~~~~~~~~~^~~~
regions.cpp:55:36: warning: comparison of integer expressions of different signedness: 'std::vector<int>::size_type' {aka 'long unsigned int'} and 'const int' [-Wsign-compare]
55 | if (positions[reg1].size() >= B) {
| ~~~~~~~~~~~~~~~~~~~~~~~^~~~
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
3 ms |
13400 KB |
Output is correct |
2 |
Correct |
4 ms |
13472 KB |
Output is correct |
3 |
Correct |
4 ms |
13400 KB |
Output is correct |
4 |
Correct |
5 ms |
13400 KB |
Output is correct |
5 |
Correct |
6 ms |
13400 KB |
Output is correct |
6 |
Correct |
10 ms |
13400 KB |
Output is correct |
7 |
Correct |
14 ms |
13400 KB |
Output is correct |
8 |
Correct |
17 ms |
13656 KB |
Output is correct |
9 |
Correct |
27 ms |
13912 KB |
Output is correct |
10 |
Correct |
44 ms |
13912 KB |
Output is correct |
11 |
Correct |
66 ms |
14168 KB |
Output is correct |
12 |
Correct |
81 ms |
14424 KB |
Output is correct |
13 |
Correct |
117 ms |
14424 KB |
Output is correct |
14 |
Correct |
174 ms |
14936 KB |
Output is correct |
15 |
Correct |
187 ms |
17240 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
1365 ms |
17648 KB |
Output is correct |
2 |
Correct |
1564 ms |
17416 KB |
Output is correct |
3 |
Correct |
2177 ms |
19300 KB |
Output is correct |
4 |
Correct |
178 ms |
14936 KB |
Output is correct |
5 |
Correct |
233 ms |
16216 KB |
Output is correct |
6 |
Correct |
397 ms |
32284 KB |
Output is correct |
7 |
Correct |
873 ms |
36648 KB |
Output is correct |
8 |
Correct |
851 ms |
60568 KB |
Output is correct |
9 |
Correct |
1652 ms |
21124 KB |
Output is correct |
10 |
Runtime error |
395 ms |
131072 KB |
Execution killed with signal 9 |
11 |
Correct |
2620 ms |
22696 KB |
Output is correct |
12 |
Correct |
830 ms |
23516 KB |
Output is correct |
13 |
Correct |
1247 ms |
24208 KB |
Output is correct |
14 |
Correct |
1394 ms |
38444 KB |
Output is correct |
15 |
Correct |
2225 ms |
28252 KB |
Output is correct |
16 |
Correct |
2308 ms |
33752 KB |
Output is correct |
17 |
Correct |
2162 ms |
46660 KB |
Output is correct |