#include <bits/stdc++.h>
typedef long long int ll;
#define INF (1e9 + 7)
#define INF2 (998244353)
#define N (ll)2e5 + 5
using namespace std;
//#define int ll
int n, g, h, t1, t2, cur = 1, q, R;
int d[N], st[N], en[N], par[N][20], r[N];
vector<int> v[N], sts[N], ens[N], r2[N];
map<int, int> m[N];
void dfs(int x, int p){
st[x] = cur++;
sts[r[x]].push_back(cur - 1);
r2[r[x]].push_back(x);
par[x][0] = p;
for(int i = 1; i<=20; i++){
par[x][i] = par[par[x][i - 1]][i - 1];
}
for(auto u : v[x]){
if(u != p)dfs(u, x);
}
en[x] = cur++;
ens[r[x]].push_back(cur - 1);
}
void solve(){
cin >> n >> R >> q;
cin >> r[1];
for(int i=2; i<=n; i++){
cin >> g >> r[i];
v[g].push_back(i);
}
dfs(1, 0);
for(int i=1; i<=q; i++){
cin >> g >> h;
if(m[g][h]){
cout << m[g][h] - 1 << endl;
continue;
}
if(sts[g].size() > sts[h].size()){
int sum=0;
for(auto u : r2[h]){
t1 = lower_bound(sts[g].begin(), sts[g].end(), st[u]) - sts[g].begin();
t2 = lower_bound(ens[g].begin(), ens[g].end(), st[u]) - ens[g].begin();
sum += t1 - t2;
}
m[g][h] = sum + 1;
cout << sum << endl;
}
else{
int sum=0;
for(auto u : r2[g]){
t1 = lower_bound(ens[h].begin(), ens[h].end(), st[u]) - ens[h].begin();
t2 = lower_bound(ens[h].begin(), ens[h].end(), en[u]) - ens[h].begin();
sum += t2 - t1;
}
m[g][h] = sum + 1;
cout << sum << endl;
}
}
}
signed main(){
ios_base::sync_with_stdio(0);
cin.tie(0);
int T = 1;
//cin>>T;
while (T--){
solve();
}
}
Compilation message
regions.cpp: In function 'void dfs(int, int)':
regions.cpp:23:19: warning: iteration 19 invokes undefined behavior [-Waggressive-loop-optimizations]
23 | par[x][i] = par[par[x][i - 1]][i - 1];
| ~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~
regions.cpp:22:21: note: within this loop
22 | for(int i = 1; i<=20; i++){
| ~^~~~
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
14 ms |
28496 KB |
Output is correct |
2 |
Correct |
15 ms |
28496 KB |
Output is correct |
3 |
Correct |
17 ms |
28468 KB |
Output is correct |
4 |
Correct |
18 ms |
28496 KB |
Output is correct |
5 |
Correct |
26 ms |
28536 KB |
Output is correct |
6 |
Correct |
37 ms |
28744 KB |
Output is correct |
7 |
Correct |
42 ms |
28768 KB |
Output is correct |
8 |
Correct |
43 ms |
28912 KB |
Output is correct |
9 |
Correct |
62 ms |
29776 KB |
Output is correct |
10 |
Correct |
99 ms |
30164 KB |
Output is correct |
11 |
Correct |
108 ms |
30948 KB |
Output is correct |
12 |
Correct |
156 ms |
32136 KB |
Output is correct |
13 |
Correct |
116 ms |
32060 KB |
Output is correct |
14 |
Correct |
260 ms |
33292 KB |
Output is correct |
15 |
Correct |
184 ms |
37960 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
959 ms |
41168 KB |
Output is correct |
2 |
Correct |
1140 ms |
40092 KB |
Output is correct |
3 |
Correct |
1810 ms |
46600 KB |
Output is correct |
4 |
Correct |
193 ms |
34032 KB |
Output is correct |
5 |
Correct |
356 ms |
37440 KB |
Output is correct |
6 |
Correct |
376 ms |
37580 KB |
Output is correct |
7 |
Correct |
677 ms |
39788 KB |
Output is correct |
8 |
Correct |
920 ms |
51152 KB |
Output is correct |
9 |
Correct |
1754 ms |
57628 KB |
Output is correct |
10 |
Correct |
3688 ms |
68016 KB |
Output is correct |
11 |
Correct |
3864 ms |
63832 KB |
Output is correct |
12 |
Correct |
1468 ms |
59200 KB |
Output is correct |
13 |
Correct |
2044 ms |
61340 KB |
Output is correct |
14 |
Correct |
2483 ms |
62812 KB |
Output is correct |
15 |
Correct |
3167 ms |
71368 KB |
Output is correct |
16 |
Correct |
3089 ms |
80872 KB |
Output is correct |
17 |
Correct |
2886 ms |
78352 KB |
Output is correct |