#include<bits/stdc++.h>
#define ll long long
#define pll pair<ll, ll>
#define pb push_back
#define mp make_pair
#define fi first
#define se second
#define ld long double
#define sz(a) ((ll)(a).size())
using namespace std;
const ll maxn=500005;
pll sp[20][maxn];
vector <pll> euler;
vector <ll> leaf, A[maxn];
ll P[maxn], col[maxn], lca[maxn], pa[maxn], dsu[maxn];
void dfs(ll u)
{
lca[u]=sz(euler)+1, euler.pb({lca[u], u});
for (ll v:A[u])
if (v!=pa[u])
pa[v]=u, dfs(v), euler.pb({lca[u], u});
if (sz(A[u])==1) leaf.pb(u);
}
void initlca()
{
ll n=sz(euler);
for (ll i=0; i<n; i++)
sp[0][i+1]=euler[i];
for (ll i=1; i<20; i++)
for (ll j=1; j+(1<<i)<=n+1; j++)
sp[i][j]=min(sp[i-1][j], sp[i-1][j+(1<<i-1)]);
}
ll LCA(ll u, ll v)
{
if (!u || !v) return u+v;
ll l=lca[u], r=lca[v];
if (l>r) swap(l, r);
ll j=__lg(r-l+1);
return min(sp[j][l], sp[j][r-(1<<j)+1]).se;
}
ll Find(ll i)
{
if (dsu[i]<0) return i;
return dsu[i]=Find(dsu[i]);
}
void Union(ll a, ll b)
{
a=Find(a), b=Find(b);
if (a==b) return;
if (dsu[a]>dsu[b]) swap(a, b);
P[a]=LCA(P[a], P[b]), dsu[a]+=dsu[b], dsu[b]=a;
}
void dfs2(ll u)
{
for (ll v:A[u])
if (v!=pa[u])
pa[v]=u, dfs2(v);
}
int main()
{
ios_base::sync_with_stdio(0);
cin.tie(0); cout.tie(0);
ll n, k; cin >> n >> k;
for (ll i=1; i<n; i++)
{
ll u, v; cin >> u >> v;
A[u].pb(v), A[v].pb(u);
}
dfs(1), initlca();
for (ll i=1; i<=n; i++)
cin >> col[i], P[col[i]]=LCA(P[col[i]], i), dsu[i]=-1;
for (ll i=1; i<=n; i++)
if (i!=P[col[i]])
Union(col[i], col[pa[i]]);
for (ll i=1; i<=n; i++) col[i]=Find(col[i]);
for (ll l:leaf) P[col[l]]=0;
for (ll i=1; i<=n; i++)
if (P[col[i]])
{
pa[i]=0, dfs2(i);
break;
}
for (ll i=1; i<=n; i++)
P[col[i]]=1;
for (ll i=1; i<=n; i++)
for (ll j:A[i])
if (j!=pa[i] && col[i]!=col[j])
P[col[i]]=0;
ll cnt=0;
for (ll l:leaf)
if (P[col[l]])
cnt++, P[col[l]]=0;
cout << (cnt+1)/2;
}
Compilation message
mergers.cpp: In function 'void initlca()':
mergers.cpp:34:53: warning: suggest parentheses around '-' inside '<<' [-Wparentheses]
34 | sp[i][j]=min(sp[i-1][j], sp[i-1][j+(1<<i-1)]);
| ~^~
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
5 ms |
24924 KB |
Output is correct |
2 |
Correct |
7 ms |
33116 KB |
Output is correct |
3 |
Correct |
7 ms |
33116 KB |
Output is correct |
4 |
Correct |
6 ms |
26972 KB |
Output is correct |
5 |
Incorrect |
6 ms |
25084 KB |
Output isn't correct |
6 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
5 ms |
24924 KB |
Output is correct |
2 |
Correct |
7 ms |
33116 KB |
Output is correct |
3 |
Correct |
7 ms |
33116 KB |
Output is correct |
4 |
Correct |
6 ms |
26972 KB |
Output is correct |
5 |
Incorrect |
6 ms |
25084 KB |
Output isn't correct |
6 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
5 ms |
24924 KB |
Output is correct |
2 |
Correct |
7 ms |
33116 KB |
Output is correct |
3 |
Correct |
7 ms |
33116 KB |
Output is correct |
4 |
Correct |
6 ms |
26972 KB |
Output is correct |
5 |
Incorrect |
6 ms |
25084 KB |
Output isn't correct |
6 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
57 ms |
115388 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
5 ms |
24924 KB |
Output is correct |
2 |
Correct |
7 ms |
33116 KB |
Output is correct |
3 |
Correct |
7 ms |
33116 KB |
Output is correct |
4 |
Correct |
6 ms |
26972 KB |
Output is correct |
5 |
Incorrect |
6 ms |
25084 KB |
Output isn't correct |
6 |
Halted |
0 ms |
0 KB |
- |