#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;
}
// Get answer for (a, b), sz[a] > BLOCK, sz[b] <= BLOCK
void genPar(int cur, int original, int cnt) {
par[ind[original]][region[cur]] += cnt;
cnt += (region[cur] == original);
for (auto a : par[cur]) {
genPar(a, original, cnt);
}
}
// 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:64:14: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
64 | while (l < sorted[reg1].size() || r < sorted[reg2].size()) {
| ~~^~~~~~~~~~~~~~~~~~~~~
regions.cpp:64:41: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
64 | while (l < sorted[reg1].size() || r < sorted[reg2].size()) {
| ~~^~~~~~~~~~~~~~~~~~~~~
regions.cpp:65:16: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
65 | if ((l < sorted[reg1].size()) && (r == sorted[reg2].size() || tin[sorted[reg1][l]] < tin[sorted[reg2][r]])) {
| ~~^~~~~~~~~~~~~~~~~~~~~
regions.cpp:65:45: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
65 | 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 |
35 ms |
94568 KB |
Output is correct |
| 2 |
Correct |
36 ms |
94628 KB |
Output is correct |
| 3 |
Correct |
39 ms |
94680 KB |
Output is correct |
| 4 |
Correct |
41 ms |
94668 KB |
Output is correct |
| 5 |
Correct |
44 ms |
94660 KB |
Output is correct |
| 6 |
Correct |
50 ms |
94720 KB |
Output is correct |
| 7 |
Correct |
56 ms |
94748 KB |
Output is correct |
| 8 |
Correct |
60 ms |
94676 KB |
Output is correct |
| 9 |
Correct |
71 ms |
95056 KB |
Output is correct |
| 10 |
Correct |
104 ms |
95148 KB |
Output is correct |
| 11 |
Correct |
135 ms |
95296 KB |
Output is correct |
| 12 |
Correct |
160 ms |
95804 KB |
Output is correct |
| 13 |
Correct |
190 ms |
95452 KB |
Output is correct |
| 14 |
Correct |
229 ms |
95976 KB |
Output is correct |
| 15 |
Correct |
270 ms |
98412 KB |
Output is correct |
| # |
결과 |
실행 시간 |
메모리 |
Grader output |
| 1 |
Runtime error |
75 ms |
131076 KB |
Execution killed with signal 9 |
| 2 |
Runtime error |
71 ms |
131076 KB |
Execution killed with signal 9 |
| 3 |
Runtime error |
75 ms |
131076 KB |
Execution killed with signal 9 |
| 4 |
Correct |
267 ms |
96080 KB |
Output is correct |
| 5 |
Correct |
395 ms |
97544 KB |
Output is correct |
| 6 |
Runtime error |
76 ms |
131076 KB |
Execution killed with signal 9 |
| 7 |
Runtime error |
80 ms |
131076 KB |
Execution killed with signal 9 |
| 8 |
Runtime error |
82 ms |
131076 KB |
Execution killed with signal 9 |
| 9 |
Correct |
2144 ms |
102320 KB |
Output is correct |
| 10 |
Runtime error |
97 ms |
131076 KB |
Execution killed with signal 9 |
| 11 |
Correct |
3159 ms |
101628 KB |
Output is correct |
| 12 |
Runtime error |
120 ms |
131076 KB |
Execution killed with signal 9 |
| 13 |
Runtime error |
112 ms |
131076 KB |
Execution killed with signal 9 |
| 14 |
Runtime error |
120 ms |
131076 KB |
Execution killed with signal 9 |
| 15 |
Runtime error |
109 ms |
131076 KB |
Execution killed with signal 9 |
| 16 |
Runtime error |
102 ms |
131076 KB |
Execution killed with signal 9 |
| 17 |
Runtime error |
117 ms |
131076 KB |
Execution killed with signal 9 |
