Submission #486617

#	Time	Username	Problem	Language	Result	Execution time	Memory
486617		cheissmart	Mergers (JOI19_mergers)	C++14	100 / 100	509 ms	52976 KiB

mergers

#include <bits/stdc++.h>
#define IO_OP std::ios::sync_with_stdio(0); std::cin.tie(0);
#define F first
#define S second
#define V vector
#define PB push_back
#define MP make_pair
#define EB emplace_back
#define ALL(v) (v).begin(), (v).end()

using namespace std;

typedef long long ll;
typedef pair<int, int> pi;
typedef V<int> vi;

string _reset = "\u001b[0m", _yellow = "\u001b[33m", _bold = "\u001b[1m";
void DBG() { cerr << "]" << _reset << endl; }
template<class H, class...T> void DBG(H h, T ...t) {
	cerr << to_string(h);
	if(sizeof ...(t)) cerr << ", ";
	DBG(t...);
}
#ifdef CHEISSMART
#define debug(...) cerr << _yellow << _bold << "Line(" << __LINE__ << ") -> [" << #__VA_ARGS__ << "]: [", DBG(__VA_ARGS__)
#else
#define debug(...)
#endif

const int INF = 1e9 + 7, N = 5e5 + 7;

vi G[N];

int p[N], lst[N], d[N], parent[N], deg[N];

void dfs(int u, int pa = 0) {
	d[u] = d[pa] + 1;
	parent[u] = pa;
	for(int v:G[u]) if(v != pa)
		dfs(v, u);
}

signed main()
{
	IO_OP;
	
	int n, k;
	cin >> n >> k;
	for(int i = 0; i < n - 1; i++) {
		int a, b;
		cin >> a >> b;
		G[a].PB(b);
		G[b].PB(a);
	}
	
	dfs(1);
	
	iota(p + 1, p + n + 1, 1);

	function<int(int)> find = [&] (int u) {
		return p[u] == u ? u : p[u] = find(p[u]); 
	};

	auto cover = [&] (int u, int v) {
		while(find(u) != find(v)){
			if(d[p[u]] > d[p[v]]) swap(u, v);
			p[p[v]] = parent[p[v]];
		}
	};
	
	for(int i = 1; i <= n; i++) {
		int s;
		cin >> s;
		if(lst[s])
			cover(lst[s], i);
		lst[s] = i;
	}
	
	for(int i = 1; i <= n; i++)
		for(int j:G[i]) if(find(i) != find(j))
			deg[p[i]]++;
	
			
	int cnt = 0;
	for(int i = 1; i <= n; i++)
		if(deg[i] == 1)	
			cnt++;
	cout << (cnt + 1) / 2 << '\n';
}

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