Submission #814712

#	Time	Username	Problem	Language	Result	Execution time	Memory
814712		WonderfulWhale	Jail (JOI22_jail)	C++17	0 / 100	11 ms	11988 KiB

jail

#include <bits/stdc++.h>
using namespace std;

#define int int64_t
#define pii pair<int, int>
#define st first
#define nd second
#define pb push_back
#define all(x) (x).begin(), (x).end()
#define sz(x) (int)(x).size()

vector<int> G[120009];
vector<int> G2[120009];
int tin[120009], tout[120009], T;
int jp2[120009][20];
int deg[120009];
pii tab[120009];

void dfs(int x, int y) {
	tin[x] = ++T;
	for(int z:G[x]) if(z!=y) dfs(z, x);
	jp2[x][0] = y;
	for(int i=1;i<20;i++) jp2[x][i] = jp2[jp2[x][i-1]][i-1];
	tout[x] = ++T;
}

bool is_ancestor(int x, int y) {
	return tin[x]<=tin[y]&&tout[x]>=tout[y];
}

int lca(int x, int y) {
	if(is_ancestor(x, y)) return x;
	if(is_ancestor(y, x)) return y;
	for(int i=19;i>=0;i--) {
		if(!is_ancestor(jp2[x][i], y)) {
			x = jp2[x][i];
		}
	}
	return jp2[x][0];
}

bool is_on_path(int x, int a, int b) {
	return is_ancestor(a, x)&&is_ancestor(x, b);
}

bool f(int x, int a, int b) {
	int y = lca(a, b);
	//cerr << "lca: " << a << " " << b << " " << y << "\n";
	//cerr << "checking: " << x << " " << a << " " << b << " " << (is_on_path(x, y, a)||is_on_path(x, y, b)) << "\n";
	return is_on_path(x, y, a)||is_on_path(x, y, b);
}

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

	int q=1;
	cin >> q;
	while(q--) {
		int n, m;
		cin >> n;
		for(int i=1;i<=n;i++) G[i].clear();
		for(int i=0;i<n-1;i++) {
			int a, b;
			cin >> a >> b;
			G[a].pb(b);
			G[b].pb(a);
		}
		tin[0] = T = 0;
		dfs(1, 0);
		tout[0] = T;
		cin >> m;
		for(int i=0;i<m;i++) {
			G2[i].clear();
			deg[i] = 0;
		}
		for(int i=0;i<m;i++) {
			cin >> tab[i].st >> tab[i].nd;
		}
		assert(f(tab[0].st, tab[0].st, tab[0].nd));
		assert(f(tab[0].nd, tab[0].st, tab[0].nd));
		assert(f(tab[1].st, tab[1].st, tab[1].nd));
		assert(f(tab[1].nd, tab[1].st, tab[1].nd));
		int a1 = f(tab[0].st, tab[1].st, tab[1].nd);
		int a2 = f(tab[0].nd, tab[1].st, tab[1].nd);
		int b1 = f(tab[1].st, tab[0].st, tab[0].nd);
		int b2 = f(tab[1].nd, tab[0].st, tab[0].nd);
		if(a1&&a2) {
			cout << "No\n";
		} else if(b1&&b2) {
			cout << "No\n";
		} else if(a1&&b1) {
			cout << "No\n";
		} else if(a2&&b2) {
			cout << "No\n";
		} else {
			cout << "Yes\n";
		}
		/*
		for(int i=0;i<m;i++) {
			for(int j=0;j<m;j++) {
				if(i==j) continue;
				if(f(tab[j].st, tab[i].st, tab[i].nd)) {
					//cerr << "adding: " << i << " " << j << "\n";
					G2[i].pb(j);
					deg[j]++;
				} 
				if(f(tab[j].nd, tab[i].st, tab[i].nd)) {
					//cerr << "adding: " << j <<  " " << i << "\n";
					G2[j].pb(i);
					deg[i]++;
				}
			}
		}
		int cnt = 0;
		queue<int> Q;
		for(int i=0;i<m;i++) {
			if(deg[i]==0) {
				Q.push(i);
			}
		}
		while(sz(Q)) {
			cnt++;
			int x = Q.front();
			Q.pop();
			for(int y:G2[x]) {
				deg[y]--;
				if(deg[y]==0) Q.push(y);
			}
		}
		if(cnt==m) {
			cout << "Yes\n";
		} else {
			cout << "No\n";
		}
		*/
	}
}

• 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