Submission #1240001

#	Time	Username	Problem	Language	Result	Execution time	Memory
1240001		kaiboy	Cities (BOI16_cities)	C++20	100 / 100	3547 ms	56872 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];
int pq[N << K], iq[(N << K) + 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++) {
		int ib = i << k ^ (hh[i] == -1 ? 0 : 1 << hh[i]);
		dd[ib] = 0, pq_add_last(ib);
	}
	while (pq_cnt) {
		int ib = pq_remove_first(), i = ib >> k, b = ib & (1 << k) - 1;
		if (b == (1 << k) - 1) {
			cout << dd[ib] << '\n';
			return 0;
		}
		for (auto jw : ejw[i]) {
			int j = jw.first, w = jw.second, jb = j << k ^ b;
			long long d = dd[ib] + w;
			if (dd[jb] > d) {
				if (dd[jb] == INF)
					pq_add_last(jb);
				dd[jb] = d, pq_up(jb);
			}
		}
		for (int c = 0; c < 1 << k; c++) {
			int ib_ = i << k ^ (b | c);
			long long d = dd[ib] + dd[i << k ^ c];
			if (dd[ib_] > d) {
				if (dd[ib_] == INF)
					pq_add_last(ib_);
				dd[ib_] = d, pq_up(ib_);
			}
		}
	}
	return 0;
}

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