Submission #415904

#	Time	Username	Problem	Language	Result	Execution time	Memory
415904		egod1537	Robot (JOI21_ho_t4)	C++14	58 / 100	3016 ms	94240 KiB

Main

#include <bits/stdc++.h>
#include <unordered_map>

using namespace std;
typedef long long ll;
struct Line {
	int to, col;
	ll cost;
	int cc;
};
struct Q {
	int pos;
	ll cost;
};
bool operator<(const Q& a, const Q& b) {
	return a.cost > b.cost;
}

vector<vector<Line>> V;

vector<vector<int>> vc;
vector<vector<int>> vidx;

vector<vector<vector<Line>>> vcole;
vector<vector<int>> colcnt;
vector<vector<ll>> colsum;

vector<ll> dst;

int main() {
	ios::sync_with_stdio(0);
	cin.tie(0), cout.tie(0);

	int n, m; cin >> n >> m;
	V.resize(n + 1);
	colcnt.resize(n + 1); colsum.resize(n + 1);
	vcole.resize(n + 1); vidx.resize(n + 1);
	vc.resize(n + 1);
	int vnum = n + 1;
	for (int i = 0; i < m; i++) {
		int from, to, col; ll cost; cin >> from >> to >> col >> cost;
		vc[from].push_back(col);
		vc[to].push_back(col);
		V[from].push_back({ to, col, cost });
		V[to].push_back({ from, col, cost });
	}

	for (int i = 1; i <= n; i++) {
		vector<int>& v = vc[i];
		sort(v.begin(), v.end());
		v.erase(unique(v.begin(), v.end()), v.end());

		int sz = v.size();
		vidx[i].resize(sz); colcnt[i].resize(sz);
		colsum[i].resize(sz); vcole[i].resize(sz);
		for (int& w : vidx[i]) w = vnum++;

		for (Line& w : V[i]) {
			int fromc = lower_bound(v.begin(), v.end(), w.col) - v.begin();
			colcnt[i][fromc]++; colsum[i][fromc] += w.cost;
			vcole[i][fromc].push_back(w);
			w.cc = fromc;
		}
	}

	dst.resize(vnum + 1, 1e18);
	for (int i = n + 1; i < vnum; i++) V.push_back(vector<Line>());

	for (int i = 1; i <= n; i++) {
		for (int w : vc[i]) {
			int col = w, idx = lower_bound(vc[i].begin(), vc[i].end(), col) - vc[i].begin();
			if (colcnt[i][idx] <= 1) continue;
			for (Line& l : vcole[i][idx])
				V[vidx[i][idx]].push_back({ l.to, l.col, colsum[i][idx] - l.cost, idx });
		}
	}
	for (int i = 1; i <= n; i++) {
		int sz = V[i].size();
		for (int j = 0; j < sz; j++) {
			Line& w = V[i][j];
			int idx = lower_bound(vc[w.to].begin(), vc[w.to].end(), w.col) - vc[w.to].begin();
			if (colcnt[w.to][idx] <= 1) continue;
			V[i].push_back({ vidx[w.to][idx], w.col, 0, idx });
		}
	}

	priority_queue<Q> pq;
	pq.push({ 1, 0 }); dst[1] = 0;
	while (!pq.empty()) {
		Q top = pq.top(); pq.pop();

		if (top.pos == n) break;

		for (Line& w : V[top.pos]) {
			ll& ret = dst[w.to];
			if (top.pos <= n) {
				if (w.to > n) {
					if (ret > top.cost) {
						ret = top.cost;
						pq.push({ w.to, ret });
					}
				}
				else {
					int idx = w.cc;
					if (colcnt[top.pos][idx] == 1) {
						if (ret > top.cost) {
							ret = top.cost;
							pq.push({ w.to, ret });
						}
					}
					else {
						if (ret > top.cost + w.cost) {
							ret = top.cost + w.cost;
							pq.push({ w.to, ret });
						}
						if (ret > top.cost + colsum[top.pos][idx] - w.cost) {
							ret = top.cost + colsum[top.pos][idx] - w.cost;
							pq.push({ w.to, ret });
						}
					}
				}
			}
			else {
				if (ret > top.cost + w.cost) {
					ret = top.cost + w.cost;
					pq.push({ w.to, ret });
				}
			}
		}
	}

	cout << (dst[n] == 1e18 ? -1 : dst[n]) << "\n";

	return 0;
}

• Subtask 1: 34 / 34
• Subtask 2: 24 / 24
• Subtask 3: 0 / 42