#include "bits/stdc++.h"
using namespace std;
using ll = long long;
#define MAXN 200005
#define MAXR 25005
#define INF (long long)1e18
#define BLOCK 450
int n, r, q;
vector<int> region(MAXN);
vector<vector<int>> adj(MAXN);
int timer = 1;
int tin[MAXN], tout[MAXN];
vector<vector<int>> sorted(MAXR); // sorted[r] stores the nodes from region r in sorted order of {tin, tout}
vector<int> ind(MAXR);
vector<vector<int>> par(BLOCK, vector<int>(MAXR));
vector<vector<int>> child(BLOCK, vector<int>(MAXR));
vector<int> largeRegions;
void dfs(int i) {
tin[i] = timer++;
sorted[region[i]].push_back(i);
for (auto a: adj[i]) {
dfs(a);
}
tout[i] = timer - 1;
}
//void genPar(int curr, int originalReg, int cnt) {
// par[ind[originalReg]][region[curr]] += cnt;
// cnt += (region[curr] == originalReg);
//
// for(auto child : adj[curr]) {
// genPar(child, originalReg, cnt);
// }
//}
void genPar(int cur, int original, int cnt) {
par[ind[original]][region[cur]] += cnt;
int newcount = cnt + (region[cur] == original);
for (auto a : par[cur]) {
genPar(a, original, newcount);
}
}
// Get answer for (a, b), sz[a] <= BLOCK, sz[b] > BLOCK
int genChild(int curr, int originalReg) {
int sub = (region[curr] == originalReg);
for(auto child : adj[curr]) {
sub += genChild(child, originalReg);
}
child[ind[originalReg]][region[curr]] += sub;
return sub;
}
bool isAnc(int a, int b) {
return tin[a] <= tin[b] && tout[b] <= tout[a];
}
int getAns(int reg1, int reg2) {
int l = 0, r = 0;
int ans = 0;
stack<int> st;
while (l < sorted[reg1].size() || r < sorted[reg2].size()) {
if ((l < sorted[reg1].size()) && (r == sorted[reg2].size() || tin[sorted[reg1][l]] < tin[sorted[reg2][r]])) {
while (!st.empty() && !isAnc(st.top(), sorted[reg1][l])) {
st.pop();
}
st.push(sorted[reg1][l]);
l++;
} else {
while (!st.empty() && !isAnc(st.top(), sorted[reg2][r])) {
st.pop();
}
ans += st.size();
r++;
}
}
return ans;
}
int main() {
ios_base::sync_with_stdio(0);
cin.tie(0); cout.tie(0);
// freopen("", "r", stdin);
// freopen("", "w", stdout);
int n, r, q; cin >> n >> r >> q;
cin >> region[1];
for (int i = 2; i <= n; i++) {
int s; cin >> s >> region[i];
adj[s].push_back(i);
}
dfs(1);
int idx = 0;
for (int i = 1; i <= r; i++) {
if (sorted[i].size() > BLOCK) {
largeRegions.push_back(i);
ind[i] = idx++;
}
}
for (auto a : largeRegions) {
genPar(1, a, 0);
genChild(1, a);
}
for (int i = 0; i < q; i++) {
int a, b; cin >> a >> b;
if (sorted[a].size() <= BLOCK && sorted[b].size() <= BLOCK) {
cout << getAns(a, b) << endl;
continue;
}
if (sorted[a].size() > BLOCK) {
cout << par[ind[a]][b] << endl;
} else {
cout << child[ind[b]][a] << endl;
}
}
}
Compilation message
regions.cpp: In function 'int getAns(int, int)':
regions.cpp:72:14: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
72 | while (l < sorted[reg1].size() || r < sorted[reg2].size()) {
| ~~^~~~~~~~~~~~~~~~~~~~~
regions.cpp:72:41: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
72 | while (l < sorted[reg1].size() || r < sorted[reg2].size()) {
| ~~^~~~~~~~~~~~~~~~~~~~~
regions.cpp:73:16: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
73 | if ((l < sorted[reg1].size()) && (r == sorted[reg2].size() || tin[sorted[reg1][l]] < tin[sorted[reg2][r]])) {
| ~~^~~~~~~~~~~~~~~~~~~~~
regions.cpp:73:45: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
73 | if ((l < sorted[reg1].size()) && (r == sorted[reg2].size() || tin[sorted[reg1][l]] < tin[sorted[reg2][r]])) {
| ~~^~~~~~~~~~~~~~~~~~~~~~
| # |
결과 |
실행 시간 |
메모리 |
Grader output |
| 1 |
Correct |
38 ms |
94656 KB |
Output is correct |
| 2 |
Correct |
39 ms |
94656 KB |
Output is correct |
| 3 |
Correct |
41 ms |
94664 KB |
Output is correct |
| 4 |
Correct |
42 ms |
94632 KB |
Output is correct |
| 5 |
Correct |
45 ms |
94684 KB |
Output is correct |
| 6 |
Correct |
57 ms |
94756 KB |
Output is correct |
| 7 |
Correct |
70 ms |
94748 KB |
Output is correct |
| 8 |
Correct |
93 ms |
94744 KB |
Output is correct |
| 9 |
Correct |
86 ms |
95176 KB |
Output is correct |
| 10 |
Correct |
105 ms |
95044 KB |
Output is correct |
| 11 |
Correct |
160 ms |
95288 KB |
Output is correct |
| 12 |
Correct |
190 ms |
95912 KB |
Output is correct |
| 13 |
Correct |
176 ms |
95416 KB |
Output is correct |
| 14 |
Correct |
260 ms |
96064 KB |
Output is correct |
| 15 |
Correct |
320 ms |
98368 KB |
Output is correct |
| # |
결과 |
실행 시간 |
메모리 |
Grader output |
| 1 |
Runtime error |
76 ms |
131076 KB |
Execution killed with signal 9 |
| 2 |
Runtime error |
87 ms |
131076 KB |
Execution killed with signal 9 |
| 3 |
Runtime error |
76 ms |
131076 KB |
Execution killed with signal 9 |
| 4 |
Correct |
282 ms |
96064 KB |
Output is correct |
| 5 |
Correct |
390 ms |
97456 KB |
Output is correct |
| 6 |
Runtime error |
76 ms |
131076 KB |
Execution killed with signal 9 |
| 7 |
Runtime error |
84 ms |
131076 KB |
Execution killed with signal 9 |
| 8 |
Runtime error |
82 ms |
131076 KB |
Execution killed with signal 9 |
| 9 |
Correct |
1959 ms |
102320 KB |
Output is correct |
| 10 |
Runtime error |
99 ms |
131076 KB |
Execution killed with signal 9 |
| 11 |
Correct |
2847 ms |
101632 KB |
Output is correct |
| 12 |
Runtime error |
138 ms |
131076 KB |
Execution killed with signal 9 |
| 13 |
Runtime error |
111 ms |
131076 KB |
Execution killed with signal 9 |
| 14 |
Runtime error |
124 ms |
131076 KB |
Execution killed with signal 9 |
| 15 |
Runtime error |
117 ms |
131076 KB |
Execution killed with signal 9 |
| 16 |
Runtime error |
107 ms |
131076 KB |
Execution killed with signal 9 |
| 17 |
Runtime error |
105 ms |
131076 KB |
Execution killed with signal 9 |
