Submission #229238

#	Time	Username	Problem	Language	Result	Execution time	Memory
229238		MetB	Burza (COCI16_burza)	C++14	0 / 160	104 ms	61048 KiB

burza

#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
 
using namespace __gnu_pbds;
 
#define N 1000003
 
using namespace std;
 
typedef long long ll;
typedef unsigned long long ull;
 
const ll INF = 1e18, MOD = 1e9 + 7, MOD2 = 1e6 + 3;

int n, k, ptr, d[20][(1 << 21)];

vector <int> g[N];
vector < pair <int, int> > v[100];

pair <int, int> dfs (int x, int p, int h) {
	if (h == k) {
		if (h) v[++ptr].push_back ({ptr, h - 1});
		return {ptr, ptr};
	}

	int l = 0, r;

	for (int to : g[x]) {
		if (to != p) {
			auto a = dfs (to, x, h + 1);
			if (!l) l = a.first;
			r = a.second;
		}
	}

	if (h && l) v[r].push_back ({l, h - 1});

	return {l, r};
}

int main () {
	cin >> n >> k;

	for (int i = 0; i < n - 1; i++) {
		int a, b;
		cin >> a >> b;
		a--, b--;
		g[a].push_back (b);
		g[b].push_back (a);
	}

	if (k * k >= n) {
		cout << "DA";
		return 0;
	}

	dfs (0, -1, 0);

	d[0][0] = 1;
	for (int i = 1; i <= ptr; i++) {
		for (int j = 0; j < (1 << k); j++) {
			for (auto a : v[i]) {
				if (j & (1 << a.second)) {
					d[i][j] |= d[a.first - 1][j ^ (1 << a.second)];
				}
			}
		}
	}

	for (int j = 0; j < (1 << k); j++)
		if (d[ptr][j]) {
			cout << "DA";
			return 0;
		}

	cout << "NE";
}

Compilation message (stderr)

burza.cpp: In function 'std::pair<int, int> dfs(int, int, int)':
burza.cpp:38:14: warning: 'r' may be used uninitialized in this function [-Wmaybe-uninitialized]
  return {l, r};
              ^

• Subtask 1: 0 / 16
• Subtask 2: 0 / 16
• Subtask 3: 0 / 16
• Subtask 4: 0 / 16
• Subtask 5: 0 / 16
• Subtask 6: 0 / 16
• Subtask 7: 0 / 16
• Subtask 8: 0 / 16
• Subtask 9: 0 / 16
• Subtask 10: 0 / 16