#include <bits/stdc++.h>
using namespace std;
const int N = 2e5+10, MR = 25010, CASE = 500;
int n, R, Q, sz[N], cnt[MR], re[N], tin[N], tout[N], ti, st[N];
vector<int> G[N], ch[N], sml[MR];
vector<vector<int>> ans;
vector<pair<int, int>> lar[MR];
void dfs1(int u, int p){
sz[u] = 1;
tin[u] = ++ti;
for(int v : G[u]){
dfs1(v, u);
sz[u] += sz[v];
}
tout[u] = ti;
}
void dfs2(int u, int p, 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, u, 0);
if(bc != -1){
dfs2(bc, u, 1);
swap(ch[u], ch[bc]);
}
ch[u].emplace_back(u);
cnt[re[u]]++;
for(int v : G[u]){
if(v == bc) continue;
for(int vv : ch[v]){
cnt[re[vv]]++;
ch[u].emplace_back(vv);
}
}
for(int i = 1; i <= R; i++) ans[re[u]][i] += cnt[i];
if(keep == 0){
for(int v : ch[u]) cnt[re[v]]--;
}
}
void chk(stack<int> st, int k){
// cout << "CHKST : ";
while(!st.empty()){
// cout << st.top() << " ";
assert(k <= st.top());
st.pop();
}
// cout << "\n";
}
int getans(int r1, int r2){
if(R <= CASE) return ans[r1][r2];
int res = 0, idx = 0;
for(int i = 0, j = -1; i < sml[r2].size(); i++){
while(idx > 0 and sml[r2][i] > st[idx]) idx--; //pop
while(j+1 < lar[r1].size() and lar[r1][j+1].second < sml[r2][i]) j++;
while(j+1 < lar[r1].size() and sml[r2][i] > lar[r1][j+1].first){ //add
if(lar[r1][j+1].second >= sml[r2][i]) st[++idx] = lar[r1][j+1].second;
j++;
}
// chk(st, sml[r2][i]);
res += idx;
}
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, -1);
if(R <= CASE){
ans.resize(R+10, vector<int>(R+10));
dfs2(1, -1, 1);
}
else {
for(int i = 1; i <= n; i++){
sml[re[i]].emplace_back(tin[i]);
lar[re[i]].emplace_back(tin[i], tout[i]);
}
for(int i = 1; i <= R; i++){
sort(sml[i].begin(), sml[i].end());
sort(lar[i].begin(), lar[i].end());
}
}
while(Q--){
int r1, r2; cin >> r1 >> r2;
cout << getans(r1, r2) << endl;
}
return 0;
}
Compilation message
regions.cpp: In function 'int getans(int, int)':
regions.cpp:61:30: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
61 | for(int i = 0, j = -1; i < sml[r2].size(); i++){
| ~~^~~~~~~~~~~~~~~~
regions.cpp:63:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
63 | while(j+1 < lar[r1].size() and lar[r1][j+1].second < sml[r2][i]) j++;
| ~~~~^~~~~~~~~~~~~~~~
regions.cpp:65:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
65 | while(j+1 < lar[r1].size() and sml[r2][i] > lar[r1][j+1].first){ //add
| ~~~~^~~~~~~~~~~~~~~~
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
5 ms |
10824 KB |
Output is correct |
2 |
Correct |
6 ms |
10824 KB |
Output is correct |
3 |
Correct |
7 ms |
10856 KB |
Output is correct |
4 |
Correct |
10 ms |
10824 KB |
Output is correct |
5 |
Correct |
13 ms |
10952 KB |
Output is correct |
6 |
Correct |
24 ms |
11208 KB |
Output is correct |
7 |
Correct |
36 ms |
11080 KB |
Output is correct |
8 |
Correct |
28 ms |
11208 KB |
Output is correct |
9 |
Correct |
46 ms |
12096 KB |
Output is correct |
10 |
Correct |
108 ms |
12280 KB |
Output is correct |
11 |
Correct |
130 ms |
12248 KB |
Output is correct |
12 |
Correct |
179 ms |
13628 KB |
Output is correct |
13 |
Correct |
117 ms |
13084 KB |
Output is correct |
14 |
Correct |
196 ms |
13128 KB |
Output is correct |
15 |
Correct |
208 ms |
17704 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
833 ms |
17428 KB |
Output is correct |
2 |
Correct |
915 ms |
16960 KB |
Output is correct |
3 |
Correct |
1319 ms |
20272 KB |
Output is correct |
4 |
Correct |
251 ms |
12872 KB |
Output is correct |
5 |
Correct |
240 ms |
14828 KB |
Output is correct |
6 |
Correct |
675 ms |
14244 KB |
Output is correct |
7 |
Correct |
976 ms |
15528 KB |
Output is correct |
8 |
Correct |
891 ms |
21696 KB |
Output is correct |
9 |
Correct |
1422 ms |
22176 KB |
Output is correct |
10 |
Correct |
2130 ms |
27912 KB |
Output is correct |
11 |
Correct |
2133 ms |
21944 KB |
Output is correct |
12 |
Correct |
1831 ms |
23188 KB |
Output is correct |
13 |
Correct |
2529 ms |
23644 KB |
Output is correct |
14 |
Correct |
2863 ms |
23508 KB |
Output is correct |
15 |
Correct |
4038 ms |
28684 KB |
Output is correct |
16 |
Correct |
4173 ms |
35676 KB |
Output is correct |
17 |
Correct |
4451 ms |
34372 KB |
Output is correct |