Submission #993793

#	Time	Username	Problem	Language	Result	Execution time	Memory
993793		zsombor	Factories (JOI14_factories)	C++17	100 / 100	3097 ms	253616 KiB

factories

#include "factories.h"
#include <iostream>
#include <vector>
#include <queue>
using namespace std;
using ll = long long;

int n, sz, C;
vector <vector <pair <int, ll>>> g(6e5);
vector <bool> del(6e5, false);
vector <int> par(6e5, -1);
vector <int> dep(6e5, 0);
vector <vector <ll>> dis(6e5, vector <ll>(20, 1e18));
vector <ll> mn(6e5, 1e18);
queue <int> q;

int get_C(int x) {
	if (del[x]) return 0;
	del[x] = true;
	int mx = 0, sum = 1;
	for (auto& p : g[x]) {
		int y = p.first, cur;
		cur = get_C(y);
		mx = max(mx, cur);
		sum += cur;
	}
	mx = max(mx, sz - sum);
	if (mx <= sz / 2) C = x;
	del[x] = false;
	return sum;
}

void dfs(int x, ll d, vector <pair <int, ll>>& v) {
	if (del[x]) return;
	del[x] = true;
	v.push_back({ x,d });
	for (auto p : g[x]) dfs(p.first, d + p.second, v);
	del[x] = false;
}

void cd(int x, int p, int d) {
	if (del[x]) return;
	sz = get_C(x);
	get_C(x);
	int c = C;
	vector <pair <int, ll>> v;
	dfs(c, 0, v);
	del[c] = true;
	par[c] = p;
	dep[c] = d;
	for (auto& p : g[c]) cd(p.first, c, d + 1);
	for (auto& p : v) dis[p.first][dep[c]] = p.second;
}

void Init(int N, int A[], int B[], int D[]) {
	n = N;
	for (int i = 0; i < n - 1; i++) {
		g[A[i]].push_back({ B[i],D[i] });
		g[B[i]].push_back({ A[i],D[i] });
	}
	cd(0, -1, 0);
}

void add(int x) {
	for (int i = x; i > -1; i = par[i]) {
		mn[i] = min(mn[i], dis[x][dep[i]]);
		q.push(i);
	}
}

ll ask(int x) {
	ll ret = 1e18;
	for (int i = x; i > -1; i = par[i]) ret = min(ret, dis[x][dep[i]] + mn[i]);
	return ret;
}

ll Query(int S, int X[], int T, int Y[]) {
	ll ans = 1e18;
	for (int i = 0; i < T; i++) add(Y[i]);
	for (int i = 0; i < S; i++) ans = min(ans, ask(X[i]));
	while (q.size()) { mn[q.front()] = 1e18; q.pop(); }
	return ans;
}

• Subtask 1: 15 / 15
• Subtask 2: 18 / 18
• Subtask 3: 67 / 67