#include <bits/stdc++.h>
#ifdef local
#define debug(a...) qqbx(#a, a)
template <typename ...T> void qqbx(const char *s, T ...a) {
int cnt = sizeof...(T);
((std::cerr << "\033[1;32m(" << s << ") = (") , ... , (std::cerr << a << (--cnt ? ", " : "\033[0m)\n")));
}
#define safe std::cerr<<__PRETTY_FUNCTION__<<" line "<<__LINE__<<" safe\n"
#else
#define debug(...) ((void)0)
#define safe ((void)0)
#endif // local
#define all(v) begin(v),end(v)
#define pb emplace_back
#define sort_uni(v) sort(all(v)), v.erase(unique(all(v)), v.end())
using namespace std;
using ll = int64_t;
template <typename T> using min_heap = priority_queue<T, vector<T>, greater<T>>;
const ll INF = 1e18;
const int maxn = 500025, inf = 1e9;
struct Segtree {
int n;
vector<int> st;
function<int(int,int)> Func;
int Id;
Segtree(int _n, function<int(int,int)> f, int id) : n(_n), st(_n * 2, id), Func(f), Id(id) {}
int& operator[](int idx) { return st[idx + n]; }
void build() {
for (int i = n-1; i > 0; i--)
st[i] = Func(st[i<<1], st[i<<1|1]);
}
int query(int l, int r) {
int res = Id;
for (l += n, r += n; l < r; l >>= 1, r >>= 1) {
if (l&1) res = Func(res, st[l++]);
if (r&1) res = Func(res, st[--r]);
}
return res;
}
};
struct Dsu {
vector<int> pa, rk;
Dsu(int n) : pa(n), rk(n) { iota(all(pa), 0); }
int anc(int x) { return x==pa[x] ? x : pa[x] = anc(pa[x]); }
bool join(int x, int y) {
if ((x=anc(x)) == (y=anc(y))) return false;
if (rk[x] < rk[y]) swap(x, y);
return pa[y] = x, rk[x] != rk[y] || ++rk[x];
}
};
vector<int> g[maxn], adj[maxn];
int color[maxn];
int pa[maxn], in[maxn], ou[maxn], tot;
int mn[maxn], mx[maxn];
void dfs(int i, int p) {
pa[i] = p;
in[i] = tot++;
for (int j: g[i]) {
if (j == p) continue;
dfs(j, i);
}
ou[i] = tot;
}
signed main() {
ios_base::sync_with_stdio(0), cin.tie(0);
int n, k;
cin >> n >> k;
for (int i = 1; i < n; i++) {
int a, b;
cin >> a >> b;
g[a].emplace_back(b);
g[b].emplace_back(a);
}
for (int i = 1; i <= n; i++) cin >> color[i];
dfs(1, 0);
for (int i = 1; i <= k; i++) mn[i] = inf, mx[i] = -inf;
for (int i = 1; i <= n; i++) {
int c = color[i];
mn[c] = min(mn[c], in[i]);
mx[c] = max(mx[c], in[i]);
}
// qx <= x <= y <= qy
// x <= qx <= qy <= y
Segtree R(n, [](int a, int b){ return max(a, b); }, 0);
Segtree L(n, [](int a, int b){ return min(a, b); }, inf);
Dsu dsu(n + 1);
for (int i = 1; i <= k; i++) {
debug(mn[i], mx[i]);
R[mn[i]] = max(R[mn[i]], mx[i]);
L[mx[i]] = min(L[mx[i]], mn[i]);
}
R.build();
L.build();
for (int i = 1; i <= n; i++) {
if (R.query(in[i], ou[i]) >= ou[i] || L.query(in[i], ou[i]) < in[i]) {
debug(i, pa[i]);
dsu.join(i, pa[i]);
}
}
vector<int> deg(n + 1);
for (int i = 1; i <= n; i++) {
for (int j: g[i]) {
int a = dsu.anc(i);
int b = dsu.anc(j);
if (a != b)
adj[a].push_back(b);
}
}
for (int i = 1; i <= n; i++) sort_uni(adj[i]);
int leaf = 0;
for (int i = 1; i <= n; i++) {
int deg = adj[i].size();
debug(deg);
if (deg == 1) ++leaf;
}
debug(leaf);
cout << (leaf + 1) / 2 << '\n';
}
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
17 ms |
23916 KB |
Output is correct |
| 2 |
Incorrect |
16 ms |
23916 KB |
Output isn't correct |
| 3 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
17 ms |
23916 KB |
Output is correct |
| 2 |
Incorrect |
16 ms |
23916 KB |
Output isn't correct |
| 3 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
17 ms |
23916 KB |
Output is correct |
| 2 |
Incorrect |
16 ms |
23916 KB |
Output isn't correct |
| 3 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
83 ms |
35604 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
17 ms |
23916 KB |
Output is correct |
| 2 |
Incorrect |
16 ms |
23916 KB |
Output isn't correct |
| 3 |
Halted |
0 ms |
0 KB |
- |
