/*input
3
1 2 1
2 3 1
3 1 2
*/
#pragma GCC optimize("O3")
#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef long double ld;
vector<ll>adj[101010];
ll pa[101010], sz[101010];
void dfs(ll i, ll p)
{
if (p != 0)
adj[i].erase(find(adj[i].begin(), adj[i].end(), p));
pa[i] = p;
sz[i] = 1;
pair<ll, ll>mx = { -1, -1};
for (ll t = 0; t < (ll)adj[i].size(); t++)
{
ll j = adj[i][t];
dfs(j, i);
sz[i] += sz[j];
mx = max(mx, {sz[j], t});
}
if (mx.second != -1)
swap(adj[i][0], adj[i][mx.second]);
}
ll timer = 1;
ll nr[101010], head[101010], tail[101010];
void hld(ll i, ll h)
{
nr[i] = timer++;
head[i] = h;
tail[h] = i;
for (ll t = 0; t < (ll)adj[i].size(); t++)
{
ll j = adj[i][t];
hld(j, t == 0 ? h : j);
}
}
struct line
{
ll cc = 0, cd = 0, dd = 0, dc = 0;
};
line merge(line a, line b)
{
line c;
c.cc = min({a.cc + b.cc, a.cc + b.dc + 1, a.cd + b.cc + 1, a.cd + b.dc});
c.cd = min({a.cc + b.cd, a.cc + b.dd + 1, a.cd + b.cd + 1, a.cd + b.dd});
c.dd = min({a.dc + b.cd, a.dc + b.dd + 1, a.dd + b.cd + 1, a.dd + b.dd});
c.dc = min({a.dc + b.cc, a.dc + b.dc + 1, a.dd + b.cc + 1, a.dd + b.dc});
return c;
}
struct ST
{
line X;
ll l, r;
ST *left, *right;
ST(ll l, ll r): l(l), r(r)
{
if (l < r)
{
left = new ST(l, (l + r) / 2);
right = new ST((l + r) / 2 + 1, r);
X = merge(left->X, right->X);
}
else
{
X.cc = 0;
X.cd = 101010;
X.dc = 101010;
X.dd = 0;
}
}
line get(ll x, ll y)
{
if (x <= l && r <= y)
return X;
if (r < x || y < l)
return line();
return merge(left->get(x, y), right->get(x, y));
}
void setC(ll x, ll w)
{
if (l == r)
{
X.cc = w;
}
else
{
if (x <= (l + r) / 2)
left->setC(x, w);
else
right->setC(x, w);
X = merge(left->X, right->X);
}
}
void setD(ll x, ll w)
{
if (l == r)
{
X.dd = w;
}
else
{
if (x <= (l + r) / 2)
left->setD(x, w);
else
right->setD(x, w);
X = merge(left->X, right->X);
}
}
} medis(0, 101010);
void initialize(int N, vector<int> A, vector<int> B)
{
for (int i = 0; i < N - 1; i++)
{
adj[A[i]].push_back(B[i]);
adj[B[i]].push_back(A[i]);
}
dfs(1, 0);
hld(1, 1);
}
ll C[101010], D[101010], V[101010];
void fix(ll v)
{
ll w = head[v];
line X = medis.get(nr[w], nr[tail[w]]);
C[pa[w]] -= min({X.cd, X.cc, X.dc + 1, X.dd + 1});
D[pa[w]] -= min({X.cd + 1, X.cc + 1, X.dc, X.dd});
if (V[v] == -1)
{
medis.setC(nr[v], C[v]);
medis.setD(nr[v], 101010);
} else if (V[v] == 1)
{
medis.setC(nr[v], 101010);
medis.setD(nr[v], D[v]);
} else
{
medis.setC(nr[v], C[v]);
medis.setD(nr[v], D[v]);
}
X = medis.get(nr[w], nr[tail[w]]);
C[pa[w]] += min({X.cd, X.cc, X.dc + 1, X.dd + 1});
D[pa[w]] += min({X.cd + 1, X.cc + 1, X.dc, X.dd});
if (v != w)
return fix(w);
else if (v != 1)
return fix(pa[v]);
}
int cat(int v)
{
V[v] = -1;
fix(v);
return min(C[0], D[0]);
}
int dog(int v)
{
V[v] = 1;
fix(v);
return min(C[0], D[0]);
}
int neighbor(int v)
{
V[v] = 0;
fix(v);
return min(C[0], D[0]);
}
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
23 ms |
18552 KB |
Output is correct |
| 2 |
Incorrect |
24 ms |
18552 KB |
Output isn't correct |
| 3 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
23 ms |
18552 KB |
Output is correct |
| 2 |
Incorrect |
24 ms |
18552 KB |
Output isn't correct |
| 3 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
23 ms |
18552 KB |
Output is correct |
| 2 |
Incorrect |
24 ms |
18552 KB |
Output isn't correct |
| 3 |
Halted |
0 ms |
0 KB |
- |
