#include <bits/stdc++.h>
#define all(x) (x).begin(), (x).end()
#ifndef ONLINE_JUDGE
template<typename T>
void pr(T a){std::cerr<<a<<std::endl;}
template<typename T,typename... Args>
void pr(T a, Args... args) {std::cerr<<a<<' ',pr(args...);}
#else
template<typename... Args>
void pr(Args... args){}
#endif
using namespace std;
constexpr int MM = 2e5+1, NN = 25001, SQ = 450;
int n, m, q;
int val[MM];
vector<int> adj[MM];
int in[MM], out[MM], t;
vector<int> nodes[MM], pos[MM];
int bid[MM];
vector<int> big;
int parcnt[NN], sub[MM];
int ans1[SQ][NN];
int ans2[NN][SQ];
void dfs(int cur, int pre){
in[cur] = ++t;
pos[val[cur]].emplace_back(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]]++;
for(auto u: adj[cur]){
if(u != pre)
dfs(u, cur);
}
parcnt[val[cur]]--;
out[cur] = t;
}
void go(int cur, int pre, int col){
sub[cur] = val[cur] == col;
for(auto u: adj[cur]){
if(u != pre){
go(u, cur, col);
sub[cur] += sub[u];
}
}
//do small to big and big to big
ans2[val[cur]][bid[col]] += sub[cur];
// pr("two", val[cur], col, sub[cur], ans2[val[cur]][bid[col]]);
}
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);
}
pos[i].reserve(size(nodes[i]));
}
dfs(1, 0);
for(int i = 0; i < size(big); i++){
go(1, 0, big[i]);
}
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(pos[b]), out[j]) - upper_bound(all(pos[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: In function 'int main()':
regions.cpp:82:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
82 | for(int i = 0; i < size(big); i++){
| ~~^~~~~~~~~~~
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
12 ms |
14444 KB |
Output is correct |
2 |
Correct |
10 ms |
14444 KB |
Output is correct |
3 |
Correct |
13 ms |
14444 KB |
Output is correct |
4 |
Correct |
14 ms |
14444 KB |
Output is correct |
5 |
Correct |
15 ms |
14444 KB |
Output is correct |
6 |
Correct |
32 ms |
14572 KB |
Output is correct |
7 |
Correct |
50 ms |
14572 KB |
Output is correct |
8 |
Correct |
45 ms |
14572 KB |
Output is correct |
9 |
Correct |
73 ms |
15084 KB |
Output is correct |
10 |
Correct |
100 ms |
14956 KB |
Output is correct |
11 |
Correct |
149 ms |
15212 KB |
Output is correct |
12 |
Correct |
187 ms |
15852 KB |
Output is correct |
13 |
Correct |
277 ms |
15340 KB |
Output is correct |
14 |
Correct |
312 ms |
15980 KB |
Output is correct |
15 |
Correct |
323 ms |
19692 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
1338 ms |
20204 KB |
Output is correct |
2 |
Correct |
1676 ms |
18540 KB |
Output is correct |
3 |
Correct |
2954 ms |
22764 KB |
Output is correct |
4 |
Correct |
347 ms |
16108 KB |
Output is correct |
5 |
Correct |
442 ms |
18412 KB |
Output is correct |
6 |
Correct |
1014 ms |
31852 KB |
Output is correct |
7 |
Correct |
2033 ms |
36972 KB |
Output is correct |
8 |
Correct |
1402 ms |
47980 KB |
Output is correct |
9 |
Correct |
2961 ms |
24300 KB |
Output is correct |
10 |
Correct |
4349 ms |
81644 KB |
Output is correct |
11 |
Correct |
5798 ms |
23660 KB |
Output is correct |
12 |
Correct |
1837 ms |
53868 KB |
Output is correct |
13 |
Correct |
2612 ms |
54508 KB |
Output is correct |
14 |
Correct |
2802 ms |
62700 KB |
Output is correct |
15 |
Correct |
4024 ms |
76524 KB |
Output is correct |
16 |
Correct |
3558 ms |
85740 KB |
Output is correct |
17 |
Correct |
3653 ms |
76140 KB |
Output is correct |