// #pragma GCC optimize("Ofast")
#include <bits/stdc++.h>
using namespace std;
template<typename T>
string tostr(const T& value) {
ostringstream oss;
oss << fixed << setprecision(7);
oss << value;
return oss.str();
}
template<typename... Args>
string fstr(const string& format, Args... args) {
string result = format;
size_t pos = 0;
size_t argIndex = 0;
auto replaceArg = [&](const auto& arg) {
pos = result.find("{}", pos);
if (pos != string::npos) {
result.replace(pos, 2, tostr(arg));
++argIndex;
}
};
(replaceArg(args), ...);
return result;
}
#define int long long
const int INF = LLONG_MAX / 2 - INT_MAX;
const int INFmem = 0x3f3f3f3f'3f3f3f3f;
const int inf = INT_MAX / 2;
const int infmem = 0x3f3f3f3f;
const int MOD = 1e9 + 7;
template<int SZ, int SZ2> struct Tree {
vector<int> adj[SZ];
int r[SZ];
void init2(int n) {
cin >> r[0]; r[0]--;
for (int i = 1; i < n; i++) {
int a; cin >> a >> r[i]; r[i]--;
adj[a].push_back(i);
}
}
int st[SZ], en[SZ], cnt=0;
vector<int> sts[SZ2], ens[SZ2];
void flatten(int nd, int par) {
st[nd] = cnt++;
sts[r[nd]].push_back(st[nd]);
for (auto i : adj[nd])
if (i != par)
flatten(i, nd, st, en, cnt);
en[nd] = cnt;
ens[r[nd]].push_back(en[nd]);
}
int s[SZ2];
};
const int maxn = 200005;
const int maxr = 25005;
const int sqrtn = 450;
const int sqrtr = 160;
// input
int n, r, q;
vector<int> adj[maxn];
int re[maxn];
int st[maxn], en[maxn], 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) {
st[nd] = cnt++;
sts[re[nd]].push_back(st[nd]);
for (auto i : adj[nd])
if (i != par)
dfs(i, nd);
en[nd] = cnt;
ens[re[nd]].push_back(en[nd]);
}
int curreg;
int dfs2(int nd, int par, int num) {
// FOR prec[CURRENT][SOMETHING], update if current is curreg
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);
// FOR prec2[SOMETHING][CURRENT], return number of currents
if (re[nd] != curreg) prec2[re[nd]][s[curreg]] += num_current;
return num_current;
}
int qry(int a, int b) {
// cout << "-----" << endl << a << ' ' << b << endl;
int cnt = 0, num = 0;
int c1 = 0, c2 = 0, c3 = 0;
// looping through sts[a], sts[b], ens[a]
while (c2 < sts[b].size() && c3 < ens[a].size()) {
// cout << sts[a][c1] << ' ' << sts[b][c2] << ' ' << ens[a][c3] << ' ' << cnt << ' ' << num << endl;
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; }
}
// cout << "____" << endl;
return num;
}
void solve() {
fill(s, s+maxr, -1); // set regions to -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); }
// precompute
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 < n; i++) {
// cout << "i " << st[i] << ' ';
// for (auto j : adj[i]) cout << st[j] << ' ';
// cout << endl;
// }
// for (int i = 0; i < 3; i++) {
// cout << "STS "; for (auto j : sts[i]) cout << j << ' '; cout << " | ENS "; for (auto j : ens[i]) cout << j << ' ';
// cout << endl;
// }
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;
}
}
// #define LOCAL
// #define CODEFORCES
signed main() {
#ifndef LOCAL
cin.tie(nullptr) -> ios::sync_with_stdio(false);
#endif
#ifdef LOCAL
freopen("main.in", "r", stdin);
#endif
int t;
#ifdef CODEFORCES
cin >> t;
#endif
#ifndef CODEFORCES
t=1;
#endif
for (int i = 1; i <= t; i++) {
#ifdef LOCAL
cout << fstr("----- Case {} -----", i) << endl;
auto startTime = clock();
#endif
solve();
#ifdef LOCAL
cout << fstr("RUNTIME: {}", (double)(clock() - startTime)/CLOCKS_PER_SEC) << endl;
cout << fstr("----- END CASE {} -----", i) << endl;
#endif
#ifdef LOCAL
#endif
}
return 0;
}
Compilation message
regions.cpp: In function 'long long int qry(long long int, long long int)':
regions.cpp:113:15: 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]
113 | while (c2 < sts[b].size() && c3 < ens[a].size()) {
| ~~~^~~~~~~~~~~~~~~
regions.cpp:113:37: 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]
113 | while (c2 < sts[b].size() && c3 < ens[a].size()) {
| ~~~^~~~~~~~~~~~~~~
regions.cpp:115:31: 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]
115 | int nxt = min(min((c1 < sts[a].size() ? sts[a][c1] : INF), sts[b][c2]), ens[a][c3]);
| ~~~^~~~~~~~~~~~~~~
regions.cpp:117:16: 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]
117 | if (c1 < sts[a].size() && sts[a][c1] == nxt) { cnt++; c1++; continue; }
| ~~~^~~~~~~~~~~~~~~
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
3 ms |
12108 KB |
Output is correct |
| 2 |
Correct |
3 ms |
11864 KB |
Output is correct |
| 3 |
Correct |
5 ms |
11864 KB |
Output is correct |
| 4 |
Correct |
5 ms |
12120 KB |
Output is correct |
| 5 |
Correct |
7 ms |
12120 KB |
Output is correct |
| 6 |
Correct |
10 ms |
12120 KB |
Output is correct |
| 7 |
Correct |
14 ms |
12120 KB |
Output is correct |
| 8 |
Correct |
21 ms |
12120 KB |
Output is correct |
| 9 |
Correct |
27 ms |
12632 KB |
Output is correct |
| 10 |
Correct |
43 ms |
12468 KB |
Output is correct |
| 11 |
Correct |
63 ms |
12920 KB |
Output is correct |
| 12 |
Correct |
70 ms |
13516 KB |
Output is correct |
| 13 |
Correct |
93 ms |
13252 KB |
Output is correct |
| 14 |
Correct |
115 ms |
13824 KB |
Output is correct |
| 15 |
Correct |
135 ms |
16936 KB |
Output is correct |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
568 ms |
23256 KB |
Output is correct |
| 2 |
Correct |
614 ms |
22100 KB |
Output is correct |
| 3 |
Correct |
1055 ms |
25336 KB |
Output is correct |
| 4 |
Correct |
149 ms |
13876 KB |
Output is correct |
| 5 |
Correct |
202 ms |
15520 KB |
Output is correct |
| 6 |
Correct |
377 ms |
37788 KB |
Output is correct |
| 7 |
Correct |
686 ms |
34812 KB |
Output is correct |
| 8 |
Correct |
679 ms |
56844 KB |
Output is correct |
| 9 |
Correct |
1138 ms |
22068 KB |
Output is correct |
| 10 |
Correct |
1504 ms |
70408 KB |
Output is correct |
| 11 |
Correct |
1754 ms |
21624 KB |
Output is correct |
| 12 |
Correct |
678 ms |
45208 KB |
Output is correct |
| 13 |
Correct |
943 ms |
45944 KB |
Output is correct |
| 14 |
Correct |
1276 ms |
55604 KB |
Output is correct |
| 15 |
Correct |
1472 ms |
60396 KB |
Output is correct |
| 16 |
Correct |
1402 ms |
67440 KB |
Output is correct |
| 17 |
Correct |
1565 ms |
66452 KB |
Output is correct |
