Submission #682747

#TimeUsernameProblemLanguageResultExecution timeMemory
682747NK_Factories (JOI14_factories)C++17
0 / 100
21 ms12372 KiB
// Success consists of going from failure to failure without loss of enthusiasm
#include <bits/stdc++.h>
#include "factories.h"

using namespace std;

#define nl '\n'

using ll = long long;
using E = array<int, 2>;

const int nax = 5e5+5;
vector<E> adj[nax];
bool vis[nax];
int par[nax], siz[nax];
ll dx[nax], dy[nax], W[nax];

const ll INFL = ll(1e18) + 10;

int find_size(int u, int p = -1) {
	if (vis[u]) return 0;
	siz[u] = 1;
	for(auto e : adj[u]) {
		auto [v, w] = e; 
		if (v == p) continue;
		siz[u] += find_size(v, u);
	}
	return siz[u];
}

int find_centroid(int u, int p, int n) {
	for(auto e : adj[u]) {
		auto [v, w] = e;
		if (v == p) continue;
		if (!vis[v] && siz[v] > n / 2) return find_centroid(v, u, n);
	}
	return u;
}

void init_centroid(int u = 0, int p = -1, int w = 0) {
	find_size(u);

	int c = find_centroid(u, -1, siz[u]);
	vis[c] = 1;
	par[c] = p, W[c] = w;
	// cout << c << " -> " << p << endl;

	for(auto e : adj[c]) {
		auto [v, wv] = e;
		if (vis[v]) continue;
		init_centroid(v, c, wv);
	}
}

void Init(int N, int A[], int B[], int D[]) {
	for(int i = 0; i < N; i++) {
		vis[i] = 0; par[i] = -1;
		siz[i] = W[i] = 0;
		dx[i] = dy[i] = INFL;
		adj[i] = {};
	}

	for(int i = 0; i < N-1; i++) {
		adj[A[i]].push_back({B[i], D[i]});
		adj[B[i]].push_back({A[i], D[i]});
	}

	init_centroid();
}

ll Query(int S, int X[], int T, int Y[]) {
	vector<int> alt;
	for(int i = 0; i < S; i++) {
		int u = X[i]; 
		// cout << u << endl;
		dx[u] = 0; alt.push_back(u);
		while(par[u] != -1) {
			// cout << "PARS: " << u << endl;
			dx[par[u]] = min(dx[par[u]], dx[u] + W[u]);
			alt.push_back(u = par[u]);
		}
		// cout << "PARS: " << u << endl;
	}

	for(int i = 0; i < T; i++) {
		int u = Y[i];
		// cout << u << endl;
		dy[u] = 0; alt.push_back(u);
		while(par[u] != -1) {
			// cout << "PART: " << u << endl;
			dy[par[u]] = min(dy[par[u]], dy[u] + W[u]);
			alt.push_back(u = par[u]);
		}
		// cout << "PART: " << u << endl;
	}

	sort(begin(alt), end(alt)); alt.erase(unique(begin(alt), end(alt)), end(alt));

	ll ans = INFL;
	for(auto u : alt) {
		// cout << u << " " << dx[u] << " + " << dy[u] << endl;
		ans = min(ans, dx[u] + dy[u]);
		dx[u] = dy[u] = INFL;
	}

	return ans;
}

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