Submission #1240164

#	Time	Username	Problem	Language	Result	Execution time	Memory
1240164		kaiboy	Cities (BOI16_cities)	C++20	100 / 100	937 ms	36020 KiB

cities

#include <algorithm>
#include <iostream>
#include <vector>

using namespace std;

const       int   N = 100000;
const       int   K = 5;
const long long INF = 0x3f3f3f3f3f3f3f3fLL;

int hh[N];
vector<pair<int, int>> ejw[N];
long long dd[N << K], dd_[N];
int pq[N], iq[N + 1], pq_cnt;

bool lt(int i, int j) {
	return dd_[i] < dd_[j];
}

int p2(int p) {
	return (p <<= 1) > pq_cnt ? 0 : p ^ (p < pq_cnt && lt(iq[p ^ 1], iq[p]));
}

void pq_up(int i) {
	int j, p, q;
	for (p = pq[i]; (q = p >> 1) && lt(i, j = iq[q]); p = q)
		iq[pq[j] = p] = j;
	iq[pq[i] = p] = i;
}

void pq_dn(int i) {
	int j, p, q;
	for (p = pq[i]; (q = p2(p)) && lt(j = iq[q], i); p = q)
		iq[pq[j] = p] = j;
	iq[pq[i] = p] = i;
}

void pq_add_last(int i) {
	iq[pq[i] = ++pq_cnt] = i;
}

int pq_remove_first() {
	int i = iq[1], j = iq[pq_cnt--];
	if (i != j)
		pq[j] = 1, pq_dn(j);
	pq[i] = 0;
	return i;
}

int main() {
	ios_base::sync_with_stdio(false), cin.tie(NULL);
	int n, k, m; cin >> n >> k >> m;
	for (int i = 0; i < n; i++)
		hh[i] = -1;
	for (int h = 0; h < k; h++) {
		int i; cin >> i, i--;
		hh[i] = h;
	}
	while (m--) {
		int i, j, w; cin >> i >> j >> w, i--, j--;
		ejw[i].push_back({ j, w });
		ejw[j].push_back({ i, w });
	}
	for (int ib = 0; ib < n << k; ib++)
		dd[ib] = INF;
	for (int i = 0; i < n; i++) {
		dd[i << k] = 0;
		if (hh[i] != -1)
			dd[i << k ^ 1 << hh[i]] = 0;
	}
	for (int b = 0; b < 1 << k; b++) {
		for (int i = 0; i < n; i++)
			if ((dd_[i] = dd[i << k ^ b]) != INF)
				pq_add_last(i);
		for (int p = pq_cnt >> 1; p; p--)
			pq_dn(iq[p]);
		while (pq_cnt) {
			int i = pq_remove_first();
			for (auto jw : ejw[i]) {
				int j = jw.first, w = jw.second;
				long long d = dd_[i] + w;
				if (dd_[j] > d) {
					if (dd_[j] == INF)
						pq_add_last(j);
					dd_[j] = d, pq_up(j);
				}
			}
		}
		for (int c = 0; c < 1 << k; c++)
			if (!(b & c))
				for (int i = 0; i < n; i++) {
					int ib_ = i << k ^ b ^ c;
					dd[ib_] = min(dd[ib_], dd_[i] + dd[i << k ^ c]);
				}
	}
	long long ans = INF;
	for (int i = 0; i < n; i++)
		ans = min(ans, dd[i << k ^ (1 << k) - 1]);
	cout << ans << '\n';
	return 0;
}

• Subtask 1: 22 / 22
• Subtask 2: 14 / 14
• Subtask 3: 15 / 15
• Subtask 4: 23 / 23
• Subtask 5: 26 / 26