Submission #994228

#	Time	Username	Problem	Language	Result	Execution time	Memory
994228		vjudge1	Jail (JOI22_jail)	C++17	0 / 100	2 ms	5724 KiB

jail

#include <iostream>
#include <vector>
using namespace std;

int n, m, sz, c;
bool ans;
vector <vector <int>> g(2e5);
vector <int> to(2e5, 0);
vector <bool> del(2e5);

void reset() {
	ans = true;
	for (int i = 1; i <= n; i++) {
		g[i].clear();
		to[i] = 0;
		del[i] = false;
	}
}

int get_c(int x) {
	if (del[x]) return 0;
	del[x] = true;
	int mx = 0, sum = 1;
	for (int i : g[x]) {

	}
	return sum;
}

void cd(int x) {
	sz = get_c(x);
	get_c(x);
}

bool dfs(int x, int y) {
	if (del[x] || to[x]) return false;
	if (x == y) return true;
	del[x] = true;
	bool ret = false;
	for (int i : g[x]) if (dfs(i, y)) ret = true;
	del[x] = false;
	return ret;
}

bool bt() {
	bool kesz = true;
	for (int i = 1; i <= n; i++) if (to[i] && to[i] != i) kesz = false;
	if (kesz) return true;

	for (int i = 1; i <= n; i++) {
		if (!to[i] || to[i] == i) continue;

		int a = to[i];
		to[i] = 0;
		bool jo = dfs(i, a);
		to[i] = a;
		if (!jo) continue;

		swap(to[i], to[a]);
		if (bt()) return true;
		swap(to[i], to[a]);
	}
	return false;
}

void solve() {
	cin >> n;
	reset();
	int a, b;
	for (int i = 0; i < n - 1; i++) {
		cin >> a >> b;
		g[a].push_back(b);
		g[b].push_back(a);
	}
	cin >> m;
	for (int i = 0; i < m; i++) {
		cin >> a >> b;
		to[a] = b;
	}
	cout << (bt() ? "YES\n" : "NO\n");
}

int main() {
	ios_base::sync_with_stdio(false);
	cin.tie(NULL);
	int t;
	cin >> t;
	while (t--) solve();
}

Compilation message (stderr)

jail.cpp: In function 'int get_c(int)':
jail.cpp:24:11: warning: unused variable 'i' [-Wunused-variable]
   24 |  for (int i : g[x]) {
      |           ^
jail.cpp:23:6: warning: unused variable 'mx' [-Wunused-variable]
   23 |  int mx = 0, sum = 1;
      |      ^~

• Subtask 1: 0 / 5
• Subtask 2: 0 / 5
• Subtask 3: 0 / 16
• Subtask 4: 0 / 28
• Subtask 5: 0 / 12
• Subtask 6: 0 / 11
• Subtask 7: 0 / 23