#include "catdog.h"
#include<bits/stdc++.h>
const int N = 1e5 + 5;
using namespace std;
void up(int&a, int b){
if (a > b) a = b;
}
struct nodeIT{
int a[2][2];
int Min(){
int ans = a[0][0];
for (int i = 0; i < 2; i++) for (int j = 0; j < 2; j++) up(ans, a[i][j]);
return ans;
}
} it[N << 2], zero;
typedef vector <int> vi;
vi G[N];
int n, num[N], p[N], chainind[N], chainst[N], chainen[N], nchain;
int node[N], pos[N], cnt;
nodeIT Merge(nodeIT le, nodeIT ri){
nodeIT ans;
for (int i = 0; i < 2; i++){
for (int j = 0; j < 2; j++){
ans.a[i][j] = N;
for (int k = 0; k < 2; k++){
for (int h = 0; h < 2; h++){
up(ans.a[i][j], le.a[i][k] + ri.a[h][j] + (k != h));
}
}
}
}
return ans;
}
void update(int i, int l, int r, int pos, int v1, int v2){
if (l > pos || pos > r) return;
if (l == r){
it[i].a[0][0] = v1;
it[i].a[1][1] = v2;
it[i].a[0][1] = it[i].a[1][0] = N;
return;
}
int mid = (l + r) >> 1;
update(i << 1, l, mid, pos, v1, v2); update(i << 1 | 1, mid+1, r, pos, v1, v2);
it[i] = Merge(it[i << 1], it[i << 1 | 1]);
}
void init(int i, int l, int r){
if (l == r){
it[i] = zero;
return;
}
int mid = (l + r) >> 1;
init(i << 1, l, mid); init(i << 1 | 1, mid+1, r);
it[i] = zero;
}
nodeIT get(int i, int l, int r, int L, int R){
if (L > r || l > R) return zero;
if (L <= l && r <= R) return it[i];
int mid = (l + r) >> 1;
return Merge(get(i << 1, l, mid, L, R), get(i << 1 | 1, mid+1, r, L, R));
}
void dfs(int u){
num[u] = 1;
for (auto v : G[u]){
if (v == p[u]) continue;
p[v] = u;
dfs(v);
num[u] += num[v];
}
}
void hld(int u){
pos[u] = ++cnt; node[cnt] = u;
chainind[u] = nchain;
int Max = -1;
for (auto v : G[u]){
if (v == p[u]) continue;
if (Max == -1 || num[Max] < num[v]) Max = v;
}
if (Max != -1) hld(Max);
else chainen[nchain] = u;
for (auto v : G[u]){
if (v == p[u] || v == Max) continue;
chainst[++nchain] = v;
hld(v);
}
}
void initialize(int N, vi A, vi B) {
n = N;
for (int i = 0; i < 2; i++) for (int j = 0; j < 2; j++) zero.a[i][j] = 0;
for (int i = 0; i < n-1; i++){
G[A[i]].push_back(B[i]);
G[B[i]].push_back(A[i]);
}
dfs(1);
chainst[++nchain] = 1;
hld(1); init(1, 1, n);
}
int cat(int v) {
update(1, 1, n, pos[v], N, 0);
return get(1, 1, n, chainst[1], chainen[1]).Min();
}
int dog(int v) {
update(1, 1, n, pos[v], 0, N);
return get(1, 1, n, chainst[1], chainen[1]).Min();
}
int neighbor(int v) {
update(1, 1, n, pos[v], 0, 0);
return get(1, 1, n, chainst[1], chainen[1]).Min();
}
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
4 ms |
2688 KB |
Output is correct |
2 |
Incorrect |
5 ms |
2688 KB |
Output isn't correct |
3 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
4 ms |
2688 KB |
Output is correct |
2 |
Incorrect |
5 ms |
2688 KB |
Output isn't correct |
3 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
4 ms |
2688 KB |
Output is correct |
2 |
Incorrect |
5 ms |
2688 KB |
Output isn't correct |
3 |
Halted |
0 ms |
0 KB |
- |