Submission #1139687

#	Time	Username	Problem	Language	Result	Execution time	Memory
1139687		vuavisao	Min-max tree (BOI18_minmaxtree)	C++20	22 / 100	150 ms	16732 KiB

minmaxtree

#include <bits/stdc++.h>
#pragma GCC optimize("O3", "unroll-loops")
using namespace std;

template<typename Lhs, typename Rhs> bool Min_self(Lhs& lhs, Rhs rhs) { if(rhs < lhs) { lhs = rhs; return true; } return false; }
template<typename Lhs, typename Rhs> bool Max_self(Lhs& lhs, Rhs rhs) { if(rhs > lhs) { lhs = rhs; return true; } return false; }

using ll = long long;

const int N = 70'000 + 10;
const int INF = 1'000'000'000;

struct LazySegTree {
	struct Node {
		int val_min = -2 * INF;
		int val_max = 2 * INF;
		int lazy_min = -2 * INF;
		int lazy_max = 2 * INF;
		Node() {};
		Node(int _val_min, int _val_max, int _lazy_min, int _lazy_max) : val_min(_val_min), val_max(_val_max), lazy_min(_lazy_min), lazy_max(_lazy_max) {};
		Node operator + (const Node& other) const {
			Node res;
			res.val_min = max(this->val_min, other.val_min);
			res.val_max = min(this->val_max, other.val_max);
			return res;
		}
	};

	int n_node = 0;
	vector<Node> tree = {};

	void resize(int _n) { n_node = _n; tree.resize((n_node << 2) + 10); };
	LazySegTree() {};
	LazySegTree(int _n) { this->resize(_n); };

	void down(int node, int l, int r) {
		Max_self(tree[node].val_min, tree[node].lazy_min);
		Min_self(tree[node].val_max, tree[node].lazy_max);
		if (l < r) {
			Max_self(tree[node << 1].lazy_min, tree[node].lazy_min);
			Max_self(tree[node << 1 | 1].lazy_min, tree[node].lazy_min);
			Min_self(tree[node << 1].lazy_max, tree[node].lazy_max);
			Min_self(tree[node << 1 | 1].lazy_max, tree[node].lazy_max);
		}
		tree[node].lazy_min = -2 * INF;
		tree[node].lazy_max = 2 * INF;
	}

	void update(int node, int l, int r, int L, int R, int val_min, int val_max) {
		down(node, l, r);
		if (l > r || L > R || l > R || L > r) return;
		if (L <= l && r <= R) {
			Max_self(tree[node].lazy_min, val_min);
			Min_self(tree[node].lazy_max, val_max);
			down(node, l, r);
			return;
		}
		int mid = (l + r) >> 1;
		update(node << 1, l, mid, L, R, val_min, val_max);
		update(node << 1 | 1, mid + 1, r, L, R, val_min, val_max);
		tree[node] = tree[node << 1] + tree[node << 1 | 1];
	}

	void Update(int l, int r, int val_min, int val_max) {
		return update(1, 1, n_node, l, r, val_min, val_max);
	}

	Node query(int node, int l, int r, int L, int R) {
		down(node, l, r);
		if (l > r || L > R || l > R || L > r) return Node();
		if (L <= l && r <= R) return tree[node];
		int mid = (l + r) >> 1;
		return query(node << 1, l, mid, L, R) + query(node << 1 | 1, mid + 1, r, L, R);
	}

	Node Query(int l, int r) {
		return query(1, 1, n_node, l, r);
	}
};

int n, q;
pair<int, int> edges[N];
vector<int> g[N];

int dist[N], parent[N], child[N];
int cnt_chain, cnt_pos;
int chain_head[N], chain_of[N], inHld[N];

LazySegTree st;
pair<int, int> couple[N];

int res[N];

void dfs(int u);
void hld(int u);
void makeHld();

void updateHld(int u, int v, int val_min, int val_max) {
	while(true) {
		if(chain_of[u] == chain_of[v]) {
			int l = inHld[u], r = inHld[v];
			if(l > r) swap(l, r);
			++l;
			st.Update(l, r, val_min, val_max);
			break;
		}
		if(dist[chain_head[chain_of[u]]] < dist[chain_head[chain_of[v]]]) swap(u, v);
		int l = inHld[chain_head[chain_of[u]]];
		int r = inHld[u];
		st.Update(l, r, val_min, val_max);
		u = parent[chain_head[chain_of[u]]];
	}
}

LazySegTree::Node queryHld(int u, int v) {
	LazySegTree::Node res;
	while(true) {
		if(chain_of[u] == chain_of[v]) {
			int l = inHld[u], r = inHld[v];
			if(l > r) swap(l, r);
			++l;
			res = res + st.Query(l, r);
			break;
		}
		if(dist[chain_head[chain_of[u]]] < dist[chain_head[chain_of[v]]]) swap(u, v);
		int l = inHld[chain_head[chain_of[u]]];
		int r = inHld[u];
		res = res + st.Query(l, r);
		u = parent[chain_head[chain_of[u]]];
	}
	return res;
}


void dfs(int u) {
	child[u] = 1;
	for(const auto& v : g[u]) {
		if(v == parent[u]) continue;
		parent[v] = u;
		dist[v] = dist[u] + 1;
		dfs(v);
		child[u] += child[v];
	}
}

void hld(int u) {
	if(chain_head[cnt_chain] == 0) chain_head[cnt_chain] = u;
	chain_of[u] = cnt_chain;
	inHld[u] = ++cnt_pos;

	int big_child = -1;
	for(const auto& v : g[u]) {
		if(v == parent[u]) continue;
		if(big_child == -1 || child[v] > child[big_child]) big_child = v;
	}

	if(big_child > -1) {
		hld(big_child);
	}

	for(const auto& v : g[u]) {
		if(v == parent[u] || v == big_child) continue;
		++cnt_chain; hld(v);
	}
}

void makeHld() {
	dist[1] = 1; dfs(1);
	cnt_chain = 1; hld(1);
}

void solve() {
	cin >> n;
	for (int i = 2; i <= n; ++i) {
		auto& [u, v] = edges[i]; cin >> u >> v;
		g[u].push_back(v);
		g[v].push_back(u);
	}
	makeHld();
	cin >> q;
	st.resize(n);
	while (q-- > 0) {
		char type; cin >> type;
		int u, v;
		int val_min = -2 * INF, val_max = 2 * INF;
		cin >> u >> v;
		if (type == 'M') {
			cin >> val_max;
		} else {
			cin >> val_min;
		}
		updateHld(u, v, val_min, val_max);
	}
	map<int, vector<int>> mp;
	set<int> is_fill;
	for (int i = 2; i <= n; ++i) {
		const auto& [u, v] = edges[i];
		auto [val_min, val_max, lazy_min, lazy_max] = queryHld(u, v);
		couple[i] = make_pair(val_min, val_max);
		
		res[i] = val_max;
		if (val_max == 2 * INF || val_min == val_max) {
			res[i] = val_min;
			is_fill.insert(val_min);
			continue;
		}
		if (val_min != val_max && val_min != -2 * INF) {
			mp[val_min].push_back(i);
		}
	}
	for (auto& [val_min, list_edges] : mp) {
		if (is_fill.find(val_min) != is_fill.end()) {
			continue;
		}
		sort(list_edges.begin(), list_edges.end(), [&] (int lhs, int rhs) -> bool {
			return couple[lhs].second < couple[rhs].second;
		});
		for (int i = 1; i < list_edges.size(); ++i) {
			int pref = list_edges[i - 1];
			int cur = list_edges[i];
			if (couple[pref].second == couple[cur].second) {
				res[pref] = val_min;
				break;
			}
		}
	}
	
	for (int i = 2; i <= n; ++i) {
		const auto& [u, v] = edges[i];
		cout << u << ' ' << v << ' ' << res[i] << '\n';
	}
}

int32_t main() {
	std::ios_base::sync_with_stdio(false);
	std::cin.tie(nullptr); std::cout.tie(nullptr);
	// int t; cin >> t;
	int t = 1;
	while (t-- > 0) {
		solve();
		// cout << '\n';
	}
	return (0 ^ 0);
}

/// Code by vuavisao

• Subtask 1: 0 / 7
• Subtask 2: 22 / 22
• Subtask 3: 0 / 29
• Subtask 4: 0 / 42