#include <bits/stdc++.h>
using namespace std;
const int N = 2e5+10, BLOCK = 500, MR = 25010;
int n, R, Q, tin[N], tout[N], sz[N], re[N], cnt[MR], ti;
unordered_map<int, int> ans[MR]; //stores answer for big regions(precompute)
vector<int> lis[MR], G[N], ch[N]; //lis[i] denotes a list of those whose region is i sorted by tin[i]
inline void add(int p, int u){
ch[p].emplace_back(u);
cnt[re[u]]++;
}
inline bool isbig(int r){
return ((int)lis[r].size() > BLOCK);
}
inline bool isAnc(int p, int u){
return (tin[p] <= tin[u] and tout[u] <= tout[p]);
}
void dfs1(int u){
sz[u] = 1;
lis[re[u]].emplace_back(u);
tin[u] = ++ti;
for(int v : G[u]) dfs1(v), sz[u] += sz[v];
tout[u] = ti;
}
void dfs2(int u, bool keep){
int bc = -1;
for(int v : G[u]) if(bc == -1 or sz[v] > sz[bc]) bc = v;
for(int v : G[u]) if(v != bc) dfs2(v, 0);
if(bc != -1){
dfs2(bc, 1);
swap(ch[bc], ch[u]);
}
add(u, u);
for(int v : G[u]){
if(v == bc) continue;
for(int vv : ch[v]){
add(u, vv);
}
}
if(isbig(re[u])){
for(int r = 1; r <= R; r++){
ans[re[u]][r] += cnt[r];
}
}
if(keep == 0){
for(int v : ch[u]) cnt[re[v]]--;
}
}
int getans(int r1, int r2){
int b = 0, s = 0, res = 0;
stack<int> st;
while(b < lis[r1].size() or s < lis[r2].size()){
if((b < lis[r1].size()) and (s == lis[r2].size() or tin[lis[r1][b]] < tin[lis[r2][s]])){
while(!st.empty() and !isAnc(st.top(), lis[r1][b])) st.pop();
st.push(lis[r1][b]);
b++;
} else {
while(!st.empty() and !isAnc(st.top(), lis[r2][s])) st.pop();
res += st.size();
s++;
}
}
return res;
}
int main(void){
ios_base::sync_with_stdio(0); cin.tie(0);
cin >> n >> R >> Q;
cin >> re[1];
for(int i = 2; i <= n; i++){
int p; cin >> p >> re[i];
G[p].emplace_back(i);
}
dfs1(1);
dfs2(1, 1);
while(Q--){
int r1, r2; cin >> r1 >> r2;
if(isbig(r1) or isbig(r2)){
cout << ans[r1][r2] << endl;
} else {
cout << getans(r1, r2) << endl;
}
}
return 0;
}
Compilation message
regions.cpp: In function 'int getans(int, int)':
regions.cpp:65:13: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
65 | while(b < lis[r1].size() or s < lis[r2].size()){
| ~~^~~~~~~~~~~~~~~~
regions.cpp:65:35: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
65 | while(b < lis[r1].size() or s < lis[r2].size()){
| ~~^~~~~~~~~~~~~~~~
regions.cpp:66:15: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
66 | if((b < lis[r1].size()) and (s == lis[r2].size() or tin[lis[r1][b]] < tin[lis[r2][s]])){
| ~~^~~~~~~~~~~~~~~~
regions.cpp:66:40: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
66 | if((b < lis[r1].size()) and (s == lis[r2].size() or tin[lis[r1][b]] < tin[lis[r2][s]])){
| ~~^~~~~~~~~~~~~~~~~
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
6 ms |
11592 KB |
Output is correct |
2 |
Correct |
5 ms |
11592 KB |
Output is correct |
3 |
Correct |
8 ms |
11592 KB |
Output is correct |
4 |
Correct |
10 ms |
11592 KB |
Output is correct |
5 |
Correct |
12 ms |
11704 KB |
Output is correct |
6 |
Correct |
16 ms |
11720 KB |
Output is correct |
7 |
Correct |
28 ms |
11720 KB |
Output is correct |
8 |
Correct |
35 ms |
11848 KB |
Output is correct |
9 |
Correct |
57 ms |
12740 KB |
Output is correct |
10 |
Correct |
86 ms |
12436 KB |
Output is correct |
11 |
Correct |
101 ms |
12812 KB |
Output is correct |
12 |
Correct |
139 ms |
13640 KB |
Output is correct |
13 |
Correct |
100 ms |
13512 KB |
Output is correct |
14 |
Correct |
254 ms |
13896 KB |
Output is correct |
15 |
Correct |
279 ms |
19144 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Incorrect |
1077 ms |
18644 KB |
Output isn't correct |
2 |
Incorrect |
1165 ms |
18044 KB |
Output isn't correct |
3 |
Incorrect |
1899 ms |
21844 KB |
Output isn't correct |
4 |
Correct |
238 ms |
14224 KB |
Output is correct |
5 |
Correct |
346 ms |
17352 KB |
Output is correct |
6 |
Correct |
894 ms |
16072 KB |
Output is correct |
7 |
Correct |
1276 ms |
17596 KB |
Output is correct |
8 |
Correct |
1204 ms |
26428 KB |
Output is correct |
9 |
Correct |
1924 ms |
24944 KB |
Output is correct |
10 |
Correct |
3015 ms |
33976 KB |
Output is correct |
11 |
Correct |
3081 ms |
27792 KB |
Output is correct |
12 |
Incorrect |
7754 ms |
28740 KB |
Output isn't correct |
13 |
Execution timed out |
8006 ms |
30484 KB |
Time limit exceeded |
14 |
Execution timed out |
8037 ms |
41620 KB |
Time limit exceeded |
15 |
Execution timed out |
8029 ms |
34572 KB |
Time limit exceeded |
16 |
Execution timed out |
8054 ms |
49824 KB |
Time limit exceeded |
17 |
Execution timed out |
8042 ms |
62284 KB |
Time limit exceeded |