#include <iostream>
#include <string>
#include <vector>
#include <queue>
#include <deque>
#include <stack>
#include <set>
#include <map>
#include <unordered_map>
#include <unordered_set>
#include <cstring>
#include <cmath>
#include <algorithm>
#include <random>
#include <complex>
#include <iomanip>
#include <cassert>
#include <functional>
using namespace std;
typedef long long ll;
const int N = 1e5 + 7;
const int Inf = 1e9;
int n;
vector <int> g[N];
int par[N];
struct Node {
int dp[2][2];
Node() {
dp[0][0] = 0;
dp[1][1] = 0;
dp[0][1] = Inf;
dp[1][0] = Inf;
}
Node operator +(const Node &other) const {
Node res;
for (int i = 0; i < 2; ++i) {
for (int j = 0; j < 2; ++j) {
res.dp[i][j] = Inf;
}
}
for (int i = 0; i < 2; ++i) {
for (int j = 0; j < 2; ++j) {
for (int k = 0; k < 2; ++k) {
for (int t = 0; t < 2; ++t) {
res.dp[i][t] = min(res.dp[i][t], dp[i][j] + other.dp[k][t] + (j != k));
}
}
}
}
return res;
}
};
int sz[N];
void dfs(int u, int p) {
par[u] = p;
if (p != -1) {
g[u].erase(find(g[u].begin(), g[u].end(), p));
}
sz[u] = 1;
for (auto v : g[u]) {
dfs(v, u);
}
sort(g[u].begin(), g[u].end(), [&] (int a, int b) {
return sz[a] > sz[b];
});
}
vector <int> e;
int in[N], st[N], en[N];
int dp[N][2];
int hld(int u, int beg) {
e.push_back(u);
in[u] = (int)e.size() - 1;
st[u] = beg;
if (!g[u].empty()) {
en[u] = hld(g[u][0], beg);
for (int i = 1; i < (int)g[u].size(); ++i) {
hld(g[u][i], g[u][i]);
}
} else {
en[u] = u;
}
return en[u];
}
Node t[4 * N];
void build(int l, int r, int v) {
if (l == r) {
t[v] = Node();
} else {
int m = (l + r) >> 1;
build(l, m, 2 * v + 1);
build(m + 1, r, 2 * v + 2);
t[v] = t[2 * v + 1] + t[2 * v + 2];
}
}
void initialize(int _n, vector <int> a, vector <int> b) {
n = _n;
for (int i = 0; i + 1 < n; ++i) {
--a[i], --b[i];
g[a[i]].push_back(b[i]);
g[b[i]].push_back(a[i]);
}
dfs(0, -1);
hld(0, 0);
build(0, n - 1, 0);
}
void modify(int id, pair <int, int> val, int l, int r, int v) {
if (l == r) {
t[v].dp[0][0] = val.first;
t[v].dp[1][1] = val.second;
t[v].dp[0][1] = Inf;
t[v].dp[1][0] = Inf;
} else {
int m = (l + r) >> 1;
if (id <= m) modify(id, val, l, m, 2 * v + 1);
else modify(id, val, m + 1, r, 2 * v + 2);
t[v] = t[2 * v + 1] + t[2 * v + 2];
}
}
Node get(int ql, int qr, int l, int r, int v) {
if (qr < l || r < ql) return Node();
if (ql <= l && r <= qr) return t[v];
int m = (l + r) >> 1;
return get(ql, qr, l, m, 2 * v + 1) + get(ql, qr, m + 1, r, 2 * v + 2);
}
void update(int v) {
//cout << "Update " << v + 1 << endl;
while (v != -1) {
Node bef = get(in[st[v]], in[en[v]], 0, n - 1, 0);
modify(in[v], make_pair(dp[v][0], dp[v][1]), 0, n - 1, 0);
//cout << "Now in " << v + 1 << ' ' << dp[v][0] << ' ' << dp[v][1] << endl;
Node aft = get(in[st[v]], in[en[v]], 0, n - 1, 0);
int u = par[st[v]];
dp[u][0] -= min(min(bef.dp[0][0], bef.dp[1][0]), min(bef.dp[0][1], bef.dp[1][1]) + 1);
dp[u][0] += min(min(aft.dp[0][0], aft.dp[1][0]), min(aft.dp[0][1], aft.dp[1][1]) + 1);
dp[u][1] -= min(min(bef.dp[0][1], bef.dp[1][1]), min(bef.dp[0][0], bef.dp[1][0]) + 1);
dp[u][1] += min(min(aft.dp[0][1], aft.dp[1][1]), min(aft.dp[0][0], aft.dp[1][0]) + 1);
v = u;
}
}
int have[N];
int get() {
int ret = Inf;
Node res = get(in[st[0]], in[en[0]], 0, n - 1, 0);
for (int i = 0; i < 2; ++i) {
for (int j = 0; j < 2; ++j) {
ret = min(ret, res.dp[i][j]);
}
}
return ret;
}
int cat(int v) {
--v;
dp[v][1] += Inf;
have[v] = 0;
update(v);
return get();
}
int dog(int v) {
--v;
dp[v][0] += Inf;
have[v] = 1;
update(v);
return get();
}
int neighbor(int v) {
--v;
if (have[v] == 0) dp[v][1] -= Inf;
else if (have[v] == 1) dp[v][0] -= Inf;
update(v);
return get();
}
#ifdef LOCAL
int main() {
ios_base::sync_with_stdio(false); cin.tie(0);
#ifdef LOCAL
freopen("input.txt", "r", stdin);
#endif
int n;
cin >> n;
vector <int> a(n - 1), b(n - 1);
for (int i = 0; i + 1 < n; ++i) {
cin >> a[i] >> b[i];
}
initialize(n, a, b);
int q;
cin >> q;
for (int i = 0; i < q; ++i) {
int t, v;
cin >> t >> v;
if (t == 1) {
cout << cat(v) << '\n';
} else if (t == 2) {
cout << dog(v) << '\n';
} else {
cout << neighbor(v) << '\n';
}
}
}
#endif
| # |
결과 |
실행 시간 |
메모리 |
Grader output |
| 1 |
Correct |
10 ms |
8952 KB |
Output is correct |
| 2 |
Incorrect |
10 ms |
8952 KB |
Output isn't correct |
| 3 |
Halted |
0 ms |
0 KB |
- |
| # |
결과 |
실행 시간 |
메모리 |
Grader output |
| 1 |
Correct |
10 ms |
8952 KB |
Output is correct |
| 2 |
Incorrect |
10 ms |
8952 KB |
Output isn't correct |
| 3 |
Halted |
0 ms |
0 KB |
- |
| # |
결과 |
실행 시간 |
메모리 |
Grader output |
| 1 |
Correct |
10 ms |
8952 KB |
Output is correct |
| 2 |
Incorrect |
10 ms |
8952 KB |
Output isn't correct |
| 3 |
Halted |
0 ms |
0 KB |
- |
