#include <bits/stdc++.h>
#define FOR(i,n) for(int i=0;i<n;i++)
#define FORE(i,a,b) for(int i = a;i<=b;i++)
#define ll long long int
#define pb push_back
#define vi vector<int>
#define ff first
#define ss second
#define vv vector
#define ii pair<int,int>
using namespace std;
const int MAXN = 5e5 + 1;
const int LOGN = 20;
int n,k;
vi g[MAXN];
int color[MAXN];
vi verticesOfColor[MAXN];
int sparseTable[LOGN][MAXN];
int depth[MAXN];
int degree[MAXN];
void dfs_setup(int node,int p = -1){
sparseTable[0][node] = p;
if(p == -1)depth[node] = -1;else depth[node] = depth[p] + 1;
for(auto e : g[node]){
if(e != p)dfs_setup(e,node);
}
}
struct DSU{
int parent[MAXN];
int ID[MAXN];
void init(){
FOR(i,n) parent[i] = i;
FOR(i,n) ID[i] = i;
}
inline int find(int a){
if(parent[a] != a)parent[a] = find(parent[a]);
return parent[a];
}
inline void merge(int a,int b){
int pa = find(a);
int pb = find(b);
if(depth[pa] > depth[pb])swap(pa,pb);
parent[pb] = pa;
//parent[pa] = pb;
//if(depth[pa] < depth[pb])ID[pb] = pa;else ID[pb] = pa;
}
inline int id(int a){
return find(a);
//return ID[find(a)];
}
inline bool isSame(int a,int b){
return find(a) == find(b);
}
} dsu;
bool done[MAXN];
int main(){
ios_base::sync_with_stdio(0);
cin.tie(0);
cin >> n >> k;
vv<ii> allE;
FOR(i,n-1){
int a,b;cin >> a >> b;a--;b--;
g[a].pb(b);g[b].pb(a);
allE.pb({a,b});
}
FOR(i,k)initialLCA[i] = -1;
dfs_setup(0);
FOR(i,n){
int a;cin >> a;a--;
color[i] = a;
verticesOfColor[a].pb(i);
}
dsu.init();
FOR(i,k){
if(verticesOfColor[i].size() == 1)continue;
FORE(j,1,(int)verticesOfColor[i].size()-1){
int node1 = dsu.id(verticesOfColor[i][j]);
int node2 = dsu.id(verticesOfColor[i][j-1]);
while(node1 != node2){
if(depth[node1] > depth[node2])swap(node1,node2);
int p = dsu.id(sparseTable[0][node2]);
if(p == -1)p = 0;
dsu.merge(p,node2);
// cout << node2 << " " << node1 << " " << p << endl;
node2 = p;
}
}
}
//FOR(i,n)cout << dsu.find(i) << endl;
for(auto e : allE)if(!dsu.isSame(e.ff,e.ss))degree[dsu.find(e.ff)]++,degree[dsu.find(e.ss)]++;
int cnt = 1;
FOR(i,n)if(degree[i] == 1)cnt++;
cout << cnt/2 << endl;
return 0;
}
Compilation message
mergers.cpp: In function 'int main()':
mergers.cpp:76:10: error: 'initialLCA' was not declared in this scope
FOR(i,k)initialLCA[i] = -1;
^~~~~~~~~~
