Submission #445463

#	Time	Username	Problem	Language	Result	Execution time	Memory
445463		wind_reaper	Mergers (JOI19_mergers)	C++17	0 / 100	48 ms	17688 KiB

mergers

#include <bits/stdc++.h>
/*
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
*/

using namespace std;
// using namespace __gnu_pbds;
using namespace chrono;

// mt19937 rng((int) std::chrono::steady_clock::now().time_since_epoch().count());
/*
template <class T> using ordered_set = tree <T, null_type, less <T>, rb_tree_tag, tree_order_statistics_node_update>;
*/

//***************** CONSTANTS *****************

const int MXN = 500'000;

//***************** GLOBAL VARIABLES *****************

vector<int> col[MXN];
int color[MXN], c, deg[MXN];

//***************** AUXILIARY STRUCTS *****************



//***************** MAIN BODY *****************

// void dfs(int u, int p){
// 	if(col[color[u]].size() == 1 && g[u].size() == 1) c++;
// 	for(int v : g[u]) if(v != p) dfs(v, u);
// }

void solve(){
	int N, K;
	cin >> N >> K;

	for(int i = 0; i < N - 1; i++){
		int u, v;
		cin >> u >> v;
		--u, --v;
		// g[u].push_back(v);
		// g[v].push_back(u);
		deg[u]++;
		deg[v]++;
	}

	for(int i = 0; i < N; i++){
		int x;
		cin >> x;
		--x;
		col[x].push_back(i);
		color[i] = x;
	}

	// dfs(0, 0);
	for(int i = 0; i < N; i++)
		if(deg[i] == 1 && col[color[i]].size() == 1) c++;

	cout << (c + 1) / 2 << '\n';
}

//***************** *****************

int32_t main(){
	ios_base::sync_with_stdio(NULL);
	cin.tie(NULL);

	#ifdef LOCAL
		auto begin = high_resolution_clock::now();
	#endif

	int tc = 1;
	// cin >> tc; 
	for (int t = 0; t < tc; t++)
		solve();

	#ifdef LOCAL 
		auto end = high_resolution_clock::now();
		cout << fixed << setprecision(4);
		cout << "Execution Time: " << duration_cast<duration<double>>(end - begin).count() << "seconds" << endl;
	#endif

	return 0;
}

/*
If code gives a WA, check for the following : 
1. I/O format

2. Are you clearing all global variables in between tests if multitests are a thing

3. Can you definitively prove the logic
*/

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