제출 #630344

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
630344		Arnch	Mergers (JOI19_mergers)	C++17	0 / 100	155 ms	98484 KiB

mergers

// oooo
/*
 har chi delet mikhad bebar ~
 gitar o ba khodet nabar! ~
 ;Amoo_Hasan;
*/

#include<bits/stdc++.h>
//#pragma GCC optimize("O3,no-stack-protector,unroll-loops")
//#pragma GCC target("avx2,fma")

using namespace std;

typedef long long ll;
typedef long double ld;

#define Sz(x) int((x).size())
#define All(x) (x).begin(), (x).end()
#define wtf(x) cout<<#x <<" : " <<x <<endl
#define mak make_pair

//constexpr int PRI = 1000696969;
constexpr ll INF = 1e18, N = 1e6 + 10, MOD = 1e9 + 7, LOG = 20;

int s[N];
int par[N][LOG], h[N], st[N], fn[N], tim;
int sz[N], pv[N];
int ans;
vector<int> vc[N], adj[N], nei[N];

void dfs(int x, int p = -1) {
	par[x][0] = p;
	for(int i = 1; i < LOG; i++) par[x][i] = par[par[x][i - 1]][i - 1];
	h[x] = h[p] + 1;
	st[x] = tim++;
	for(auto j : adj[x]) {
		if(j == p) continue;
		dfs(j, x);
	}
	fn[x] = tim;
}
int get_par(int x, int y) {
	for(int i = 0; i < LOG; i++)
		if((y >> i) & 1)
			x = par[x][i];
	return x;
}
int lca(int x, int y) {
	if(h[x] > h[y]) swap(x, y);
	y = get_par(y, h[y] - h[x]);
	if(x == y) return x;
	for(int i = LOG - 1; i >= 0; i--)
		if(par[x][i] != par[y][i])
			x = par[x][i], y = par[y][i];
	return par[x][0];
}

int find(int x) {
	if(pv[x] == x) return x;
	return pv[x] = find(pv[x]);
}
void merge(int x, int y) {
	int X = find(x), Y = find(y);
	if(X == Y) return;
	if(sz[X] < sz[Y]) swap(X, Y);
	pv[Y] = X, sz[X] += sz[Y];
}

bool cmp(int i, int j) {
	return st[i] < st[j];
}
void solve(int x) {
	vector<int> ver;
	for(auto i : vc[x]) ver.push_back(i);
	sort(All(ver), cmp);
	int sz = Sz(ver);
	for(int i = 1; i < sz; i++) {
		ver.push_back(lca(ver[i - 1], ver[i]));
	}
	sort(All(ver), cmp);
	ver.erase(unique(All(ver)), ver.end());

	stack<int> mt;
	mt.push(ver[0]);

	merge(ver[0], x);
	for(int i = 1; i < Sz(ver); i++) {
		int v = ver[i];
		while(fn[mt.top()] < fn[v]) mt.pop();
		int p = mt.top();

		merge(x, v);
		v = par[v][0];
		while(v != p) {
			merge(x, v);
			v = par[v][0];
		}
		mt.push(v);
	}
}

int main() {
	ios :: sync_with_stdio(0), cin.tie(0); cout.tie(0);

	for(int i = 0; i < N; i++) sz[i] = 1, pv[i] = i;

	int n, k; cin >>n >>k;
	for(int i = 0; i < n - 1; i++) {
		int u, v; cin >>u >>v;
		--u, --v;
		adj[u].push_back(v), adj[v].push_back(u);
	}
	for(int i = 0; i < n; i++) {
		cin >>s[i];
		--s[i], s[i] += n;
		vc[s[i]].push_back(i);
	}

	dfs(0);

	for(int i = n; i < n + k; i++) {
		solve(i);
	}

	for(int i = 0; i < n; i++) {
		for(auto j : adj[i]) {
			if(pv[j] == pv[i]) continue;
			nei[pv[j]].push_back(pv[i]);
			nei[pv[i]].push_back(pv[j]);
		}
	}

	for(int i = 0; i < N; i++) {
		nei[i].erase(unique(All(nei[i])), nei[i].end());
		if(Sz(nei[i]) == 1) ans++;
	}
	cout<<(ans + 1) / 2;

	return 0;
}

• Subtask 1: 0 / 10
• Subtask 2: 0 / 24
• Subtask 3: 0 / 14
• Subtask 4: 0 / 22
• Subtask 5: 0 / 30