#include <bits/stdc++.h>
#define all(x) (x).begin(), (x).end()
using namespace std;
const int MM = 2e5+5, NN = 25000, SQ = 501;
int n, m, q;
int val[MM];
vector<int> adj[MM];
int in[MM], out[MM], t;
map<int, int> cnt[MM], parcnt;
vector<int> nodes[MM];
int bit[MM], bid[MM];
vector<int> big;
int ans1[SQ][NN];
int ans2[NN][SQ]; //swap order if still not fast enough
void update(int i, int v){
for(; i < MM; i += i&-i)
bit[i] += v;
}
int query(int i){
int v = 0;
for(; i; i -= i&-i)
v += bit[i];
return v;
}
void dfs(int cur, int pre){
in[cur] = ++t;
if(size(nodes[val[cur]]) < SQ){
//do big to small only
for(int i = 0; i < size(big); i++)
ans1[i][val[cur]] += parcnt[big[i]];
}
parcnt[val[cur]]++;
int id = 0;
for(auto u: adj[cur]){
if(u != pre){
dfs(u, cur);
if(size(cnt[u]) > size(cnt[id]))
id = u;
}
}
cnt[cur] = move(cnt[id]);
for(auto u: adj[cur]){
if(u != pre and u != id){
for(auto [a, c]: cnt[u]){
cnt[cur][a] += c;
}
cnt[u].clear();
}
}
cnt[cur][val[cur]]++;
//do small to big and big to big
for(int i = 0; i < size(big); i++)
ans2[val[cur]][i] += cnt[cur][big[i]];
if(!--parcnt[val[cur]]){
parcnt.erase(val[cur]);
}
out[cur] = t;
}
int main(){
cin>>n>>m>>q;
cin>>val[1];
nodes[val[1]].emplace_back(1);
for(int i = 2,p; i <= n; i++){
cin>>p>>val[i];
adj[p].emplace_back(i);
nodes[val[i]].emplace_back(i);
}
for(int i = 1; i <= m; i++){
if(size(nodes[i]) >= SQ){
bid[i] = size(big);
big.emplace_back(i);
}
}
dfs(1, 0);
for(int i = 1; i <= m; i++){
for(int &j: nodes[i])
j = in[j];
}
for(int i = 0,a,b; i < q; i++){
cin>>a>>b;
if(size(nodes[b]) >= SQ){
cout<<ans2[a][bid[b]]<<'\n';
}
else if(size(nodes[a]) >= SQ){
cout<<ans1[bid[a]][b]<<'\n';
}
else{
int ret = 0;
for(int j: nodes[a]){
ret += upper_bound(all(nodes[b]), out[j]) - lower_bound(all(nodes[b]), in[j]);
}
cout<<ret<<'\n';
}
cout<<flush;
}
}
/*
precompute big-small, small-small, small-big
brute force small-small
*/
Compilation message
regions.cpp: In function 'void dfs(int, int)':
regions.cpp:35:20: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
35 | for(int i = 0; i < size(big); i++)
| ~~^~~~~~~~~~~
regions.cpp:60:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
60 | for(int i = 0; i < size(big); i++)
| ~~^~~~~~~~~~~
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
13 ms |
19180 KB |
Output isn't correct |
2 |
Incorrect |
13 ms |
19180 KB |
Output isn't correct |
3 |
Incorrect |
15 ms |
19180 KB |
Output isn't correct |
4 |
Incorrect |
17 ms |
19196 KB |
Output isn't correct |
5 |
Incorrect |
20 ms |
19180 KB |
Output isn't correct |
6 |
Correct |
32 ms |
19308 KB |
Output is correct |
7 |
Incorrect |
35 ms |
19180 KB |
Output isn't correct |
8 |
Incorrect |
45 ms |
19308 KB |
Output isn't correct |
9 |
Correct |
63 ms |
20204 KB |
Output is correct |
10 |
Incorrect |
104 ms |
19820 KB |
Output isn't correct |
11 |
Incorrect |
142 ms |
20076 KB |
Output isn't correct |
12 |
Incorrect |
163 ms |
20972 KB |
Output isn't correct |
13 |
Incorrect |
212 ms |
20076 KB |
Output isn't correct |
14 |
Incorrect |
314 ms |
20844 KB |
Output isn't correct |
15 |
Correct |
323 ms |
27372 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
1268 ms |
25720 KB |
Output isn't correct |
2 |
Incorrect |
1322 ms |
23160 KB |
Output isn't correct |
3 |
Incorrect |
2436 ms |
29712 KB |
Output isn't correct |
4 |
Incorrect |
369 ms |
21228 KB |
Output isn't correct |
5 |
Incorrect |
307 ms |
25228 KB |
Output isn't correct |
6 |
Incorrect |
1108 ms |
23276 KB |
Output isn't correct |
7 |
Incorrect |
1525 ms |
24044 KB |
Output isn't correct |
8 |
Incorrect |
1629 ms |
35564 KB |
Output isn't correct |
9 |
Incorrect |
2520 ms |
30956 KB |
Output isn't correct |
10 |
Incorrect |
4550 ms |
43372 KB |
Output isn't correct |
11 |
Incorrect |
4040 ms |
29420 KB |
Output isn't correct |
12 |
Incorrect |
1640 ms |
61932 KB |
Output isn't correct |
13 |
Incorrect |
1770 ms |
63172 KB |
Output isn't correct |
14 |
Incorrect |
2893 ms |
72300 KB |
Output isn't correct |
15 |
Incorrect |
3314 ms |
91508 KB |
Output isn't correct |
16 |
Incorrect |
3445 ms |
109848 KB |
Output isn't correct |
17 |
Incorrect |
3818 ms |
96932 KB |
Output isn't correct |