Submission #873865

#	Time	Username	Problem	Language	Result	Execution time	Memory
873865		MinaRagy06	Tourism (JOI23_tourism)	C++17	28 / 100	5072 ms	18412 KiB

tourism

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

const int N = 100'005;
vector<int> adj[N];
int h[N], st[N], en[N], t, anc[17][N];
void dfs(int i, int p, int d) {
	anc[0][i] = p;
	for (int j = 1; j < 17; j++) {
		anc[j][i] = anc[j - 1][anc[j - 1][i]];
	}
	h[i] = d;
	st[i] = t++;
	for (auto nxt : adj[i]) {
		if (nxt == p) continue;
		dfs(nxt, i, d + 1);
	}
	en[i] = t - 1;
}
int lca(int u, int v) {
	if (st[u] > st[v]) swap(u, v);
	if (st[u] <= st[v] && en[v] <= en[u]) {
		return u;
	}
	for (int j = 16; j >= 0; j--) {
		if (!(st[anc[j][u]] <= st[v] && en[v] <= en[anc[j][u]])) {
			u = anc[j][u];
		}
	}
	return anc[0][u];
}
int main() {
	ios_base::sync_with_stdio(0), cin.tie(0);
	int n, m, q;
	cin >> n >> m >> q;
	for (int i = 1, u, v; i < n; i++) {
		cin >> u >> v;
		adj[u].push_back(v);
		adj[v].push_back(u);
	}
	dfs(1, 1, 1);
	int a[m];
	for (int i = 0; i < m; i++) {
		cin >> a[i];
	}
	while (q--) {
		int l, r;
		cin >> l >> r;
		l--, r--;
		vector<int> cur;
		for (int i = l; i <= r; i++) {
			cur.push_back(a[i]);
		}
		sort(cur.begin(), cur.end(), [&] (int x, int y) {return st[x] < st[y];});
		int ans = h[cur[0]] - h[lca(cur[0], cur.back())] + 1;
		for (int i = 1; i < cur.size(); i++) {
			ans += h[cur[i]] - h[lca(cur[i], cur[i - 1])];
		}
		cout << ans << '\n';
	}
	return 0;
}

Compilation message (stderr)

tourism.cpp: In function 'int main()':
tourism.cpp:57:21: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   57 |   for (int i = 1; i < cur.size(); i++) {
      |                   ~~^~~~~~~~~~~~

• Subtask 1: 5 / 5
• Subtask 2: 5 / 5
• Subtask 3: 0 / 7
• Subtask 4: 18 / 18
• Subtask 5: 0 / 24
• Subtask 6: 0 / 41