// #pragma GCC optimize("Ofast")
#include <bits/stdc++.h>
using namespace std;
#define int long long
const int INF = LLONG_MAX / 2 - INT_MAX;
const int maxn = 200005;
const int maxr = 25005;
const int sqrtn = 450;
const int sqrtr = 160;
int n, r, q;
vector<int> adj[maxn];
int re[maxn];
int cnt = 0;
vector<int> sts[maxr], ens[maxr];
int s[maxr], prec[sqrtr][maxr], prec2[maxr][sqrtr], cnt2 = 0;
void dfs(int nd, int par) {
sts[re[nd]].push_back(cnt++);
for (auto i : adj[nd])
if (i != par)
dfs(i, nd);
ens[re[nd]].push_back(cnt);
}
int curreg;
int dfs2(int nd, int par, int num) {
if (re[nd] != curreg) prec[s[curreg]][re[nd]] += num;
num += re[nd] == curreg;
int num_current = re[nd] == curreg;
for (auto i : adj[nd])
if (i != par)
num_current += dfs2(i, nd, num);
if (re[nd] != curreg) prec2[re[nd]][s[curreg]] += num_current;
return num_current;
}
int qry(int a, int b) {
int cnt = 0, num = 0;
int c1 = 0, c2 = 0, c3 = 0;
while (c2 < sts[b].size() && c3 < ens[a].size()) {
int nxt = min(min((c1 < sts[a].size() ? sts[a][c1] : INF), sts[b][c2]), ens[a][c3]);
if (ens[a][c3] == nxt) { cnt--; c3++; continue; }
if (c1 < sts[a].size() && sts[a][c1] == nxt) { cnt++; c1++; continue; }
if (sts[b][c2] == nxt) { num += cnt; c2++; continue; }
}
return num;
}
signed main() {
cin.tie(nullptr) -> ios::sync_with_stdio(false);
fill(s, s+maxr, -1);
cin >> n >> r >> q;
cin >> re[0]; re[0]--;
for (int i = 1; i < n; i++)
{ int a; cin >> a >> re[i]; a--, re[i]--; adj[a].push_back(i); }
dfs(0, 0);
for (int i = 0; i < r; i++)
if (sts[i].size() >= sqrtn) {
s[i] = cnt2++; curreg = i;
dfs2(0, 0, 0);
}
for (int i = 0; i < q; i++) {
int a, b; cin >> a >> b; a--, b--;
if (s[a] != -1) {cout << prec[s[a]][b] << endl; continue;}
if (s[b] != -1) {cout << prec2[a][s[b]] << endl; continue;}
cout << qry(a, b) << endl;
}
}
Compilation message
regions.cpp: In function 'long long int qry(long long int, long long int)':
regions.cpp:49:15: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
49 | while (c2 < sts[b].size() && c3 < ens[a].size()) {
| ~~~^~~~~~~~~~~~~~~
regions.cpp:49:37: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
49 | while (c2 < sts[b].size() && c3 < ens[a].size()) {
| ~~~^~~~~~~~~~~~~~~
regions.cpp:50:31: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
50 | int nxt = min(min((c1 < sts[a].size() ? sts[a][c1] : INF), sts[b][c2]), ens[a][c3]);
| ~~~^~~~~~~~~~~~~~~
regions.cpp:52:16: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
52 | if (c1 < sts[a].size() && sts[a][c1] == nxt) { cnt++; c1++; continue; }
| ~~~^~~~~~~~~~~~~~~
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
2 ms |
8792 KB |
Output is correct |
| 2 |
Correct |
2 ms |
8792 KB |
Output is correct |
| 3 |
Correct |
3 ms |
8792 KB |
Output is correct |
| 4 |
Correct |
4 ms |
8792 KB |
Output is correct |
| 5 |
Correct |
5 ms |
8792 KB |
Output is correct |
| 6 |
Correct |
10 ms |
9048 KB |
Output is correct |
| 7 |
Correct |
19 ms |
9048 KB |
Output is correct |
| 8 |
Correct |
17 ms |
9300 KB |
Output is correct |
| 9 |
Correct |
26 ms |
9560 KB |
Output is correct |
| 10 |
Correct |
51 ms |
9304 KB |
Output is correct |
| 11 |
Correct |
67 ms |
9816 KB |
Output is correct |
| 12 |
Correct |
81 ms |
10240 KB |
Output is correct |
| 13 |
Correct |
92 ms |
10144 KB |
Output is correct |
| 14 |
Correct |
117 ms |
10700 KB |
Output is correct |
| 15 |
Correct |
135 ms |
13812 KB |
Output is correct |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
602 ms |
20128 KB |
Output is correct |
| 2 |
Correct |
693 ms |
18976 KB |
Output is correct |
| 3 |
Correct |
1098 ms |
22204 KB |
Output is correct |
| 4 |
Correct |
164 ms |
10748 KB |
Output is correct |
| 5 |
Correct |
216 ms |
12812 KB |
Output is correct |
| 6 |
Correct |
403 ms |
34488 KB |
Output is correct |
| 7 |
Correct |
707 ms |
31708 KB |
Output is correct |
| 8 |
Correct |
657 ms |
53916 KB |
Output is correct |
| 9 |
Correct |
1160 ms |
18936 KB |
Output is correct |
| 10 |
Correct |
1573 ms |
67676 KB |
Output is correct |
| 11 |
Correct |
1749 ms |
18496 KB |
Output is correct |
| 12 |
Correct |
725 ms |
42000 KB |
Output is correct |
| 13 |
Correct |
1052 ms |
42548 KB |
Output is correct |
| 14 |
Correct |
1430 ms |
52724 KB |
Output is correct |
| 15 |
Correct |
1626 ms |
57304 KB |
Output is correct |
| 16 |
Correct |
1599 ms |
64404 KB |
Output is correct |
| 17 |
Correct |
1667 ms |
63304 KB |
Output is correct |
