#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using pii = pair<int, int>;
#define pb push_back
#define ff first
#define ss second
#define ins insert
int main(){
ios_base::sync_with_stdio(0);
cin.tie(0);
cout.tie(0);
int n, k; cin>>n>>k;
vector<int> g[n + 1];
for (int i = 1; i < n; i++){
int x, y; cin>>x>>y;
g[x].pb(y);
g[y].pb(x);
}
vector<int> s(n + 1), all[k + 1];
for (int i = 1; i <= n; i++){
cin>>s[i];
all[s[i]].pb(i);
}
vector<int> sz(n + 1), h(n + 1), d(n + 1), p(n + 1);
function<void(int, int)> fill = [&](int v, int pr){
p[v] = pr;
d[v] = d[pr] + 1;
sz[v] = 1;
for (int i: g[v]){
if (i == pr) continue;
fill(i, v);
if (sz[i] > sz[h[v]]){
h[v] = i;
}
sz[v] += sz[i];
}
};
fill(1, 0);
vector<int> head(n + 1), pos(n + 1);
int timer = 0;
function<void(int, int)> fill_hld = [&](int v, int k){
head[v] = k;
pos[v] = ++timer;
if (!h[v]) return;
fill_hld(h[v], k);
for (int i: g[v]){
if (pos[i]) continue;
fill_hld(i, i);
}
};
fill_hld(1, 1);
set<int> st;
for (int i = 2; i <= n; i++) st.ins(i);
auto rem = [&](int l, int r){
auto it1 = st.lower_bound(l), it2 = st.upper_bound(r);
st.erase(it1, it2);
};
auto upd = [&](int x, int y){
while (head[x] != head[y]){
if (d[head[x]] > d[head[y]]){
swap(x, y);
}
rem(pos[head[y]] + 1, pos[y]);
y = p[head[y]];
}
if (d[x] > d[y]) swap(x, y);
rem(pos[x] = 1, pos[y]);
};
for (int i = 1; i <= k; i++){
for (int j = 0; j + 1 < all[i].size(); j++){
upd(all[i][j], all[i][j + 1]);
}
}
vector<int> inv(n + 1);
for (int i = 1; i <= n; i++) inv[pos[i]] = i;
vector<bool> ban(n + 1);
vector<int> bd;
for (int i: st){
bd.pb(inv[i]);
ban[inv[i]] = 1;
}
auto f = [&](int x, int y){
return (d[x] > d[y]) ? x : y;
};
vector<int> gr(n + 1);
timer = 0;
function<void(int)> dfs = [&](int v){
gr[v] = timer;
for (int i: g[v]){
if (gr[i] || ban[f(i, v)]) continue;
dfs(i);
}
};
for (int i = 1; i <= n; i++){
if (!gr[i]){
timer++;
dfs(i);
}
}
if (timer == 1){
cout<<0<<"\n";
return 0;
}
vector<int> cc(timer + 1);
for (int i: bd){
cc[gr[i]]++;
cc[gr[p[i]]]++;
}
int tot = 0;
for (int i = 1; i <= timer; i++) tot += (cc[i] == 1);
cout<<(tot + 1) / 2<<"\n";
}
Compilation message
mergers.cpp: In function 'int main()':
mergers.cpp:79:31: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
79 | for (int j = 0; j + 1 < all[i].size(); j++){
| ~~~~~~^~~~~~~~~~~~~~~
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
0 ms |
344 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
0 ms |
344 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
0 ms |
344 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
85 ms |
17228 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
0 ms |
344 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
