Submission #651234

#	Time	Username	Problem	Language	Result	Execution time	Memory
651234		ccctttd	Birthday gift (IZhO18_treearray)	C++14	0 / 100	1 ms	212 KiB

treearray

#include<iostream>
#include<vector>
#include<algorithm>
#include<climits>
#include<cmath>
#include<cassert>
#include<stack>
#include<queue>
#include<set>
#include<map>


using namespace std;

vector<int>depth;
vector<vector<int>>edges;
vector<vector<int>>anc;

void dfs(int root, int dep) {
	depth[root] = dep;
	for (auto i : edges[root]) {
		if (anc[root][0] != i) {
			anc[i][0] = root;
			dfs(i, dep + 1);
		}
	}
}

void init(int n) {
	depth.resize(n + 1, 0);
	edges.resize(n + 1);
	anc.resize(n + 1, vector<int>(18));
	for (int i = 0; i < n - 1; i++) {
		int u, v;
		cin >> u >> v;
		edges[u].push_back(v);
		edges[v].push_back(u);
	}
	dfs(1, 1);
	for (int i = 1; i < 18; i++) {
		for (int j = 1; j <= n; j++) {
			anc[j][i] = anc[anc[j][i - 1]][i - 1];
		}
	}
}

int lca(int u, int v) {
	if (depth[u] < depth[v])swap(u, v);
	int k = depth[u] - depth[v];
	for (int i = 0; k; i++) {
		if (k & 1)u = anc[u][i];
		k >>= 1;
	}
	for (int i = 17; i >= 0; i--) {
		if (anc[u][i] != anc[v][i]) {
			u = anc[u][i];
			v = anc[v][i];
		}
	}
	if (u == v)return u;
	return anc[u][0];
}

vector<int>seq;

pair<int, int>dc(int l, int r, int v) {
	if (l == r) {
		if (seq[l] == v)return make_pair(l, l);
		else return make_pair(-1, -1);
	}
	int m = (l + r) >> 1;
	pair<int, int>lans = dc(l, m, v), rans = dc(m + 1, r, v);
	if (lans.first != -1)return lans;
	if (rans.first != -1)return rans;
	set<int>cofv;
	vector<int>ret;
	for (int lm = m, llca = seq[m]; lm >= l; lm--) {
		llca = lca(llca, seq[lm]);
		if (depth[llca] <= depth[v])break;
		int step = depth[llca] - depth[v] - 1;
		int temp = llca;
		assert(step >= 0);
		for (int i = 0; step; i++) {
			if (step & 1)temp = anc[temp][i];
			step >>= 1;
		}
		if (!cofv.count(temp)) {
			cofv.insert(temp);
			ret.push_back(lm);
		}
	}
	for (int rm = m + 1, rlca = seq[m + 1]; rm <= r; rm++) {
		rlca = lca(rlca, seq[rm]);
		if (depth[rlca] <= depth[v])break;
		int step = depth[rlca] - depth[v] - 1;
		int temp = rlca;
		assert(step >= 0);
		for (int i = 0; step; i++) {
			if (step & 1)temp = anc[temp][i];
			step >>= 1;
		}
		if (!cofv.count(temp)) {
			cofv.insert(temp);
			ret.push_back(rm);
		}
	}
	if (cofv.size() == 2) {
		return make_pair(min(ret[0], ret[1]), max(ret[0], ret[1]));
	}
	return make_pair(-1, -1);
}

void solve() {
	int n, m, q;
	cin >> n >> m >> q;
	init(n);
	seq.resize(m + 1);
	for (int i = 1; i <= m; i++) {
		cin >> seq[i];
	}
	for (int i = 0; i < q; i++) {
		int c;
		cin >> c;
		if (c == 1) {
			int pos, v;
			cin >> pos >> v;
			seq[pos] = v;
		}
		else {
			int l, r, v;
			cin >> l >> r >> v;
			pair<int, int>ans = dc(l, r, v);
			cout << ans.first << ' ' << ans.second << endl;
		}
	}
}




int main() {
	ios_base::sync_with_stdio(false), cin.tie(0);
	solve();
}

• Subtask 1: 0 / 12
• Subtask 2: 0 / 18
• Subtask 3: 0 / 26
• Subtask 4: 0 / 44