Submission #1130312

#	Time	Username	Problem	Language	Result	Execution time	Memory
1130312		am_aadvik	Olympic Bus (JOI20_ho_t4)	C++17	0 / 100	1103 ms	189592 KiB

ho_t4

#include <iostream>
#include<set>
#include<map>
#include<vector>
#define int long long
const int inf = 1e17;
using namespace std;

vector<vector<int>> g[2][205];
vector<vector<int>> dist[2]; //path, node, rev. edg
int32_t main()
{
	int n, m; cin >> n >> m;
	dist[0].assign(n + 1, vector<int>(m + 1, inf));
	dist[1].assign(n + 1, vector<int>(m + 1, inf));

	for (int i = 1; i <= m; ++i) {
		int u, v, c, d; cin >> u >> v >> c >> d;
		g[0][u].push_back({ v, c ,d, i });
		g[1][v].push_back({ u, c, d, i });
	}

	set<vector<int>> s; //{dist+cost, node, path, rev. edg.}
	s.insert({ 0, 1, 0, 0 }), dist[0][1][0] = 0;
	while (s.size()) {
		vector<int> f = *s.begin();
		s.erase(s.begin());
		if (f[2] && (f[1] == 1)) { //complete!
			cout << f[0];
			return 0;
		}

		if (f[1] == n) f[2] = 1; //1 way complete!
		for (auto x : g[0][f[1]]) { //out edgs.
			if (f[3] != x[3]) { //this edg. wasnt rev.
				int val = dist[f[2]][x[0]][f[3]];
				if (val > (f[0] + x[1])) {
					if (val != inf)
						s.erase({ val, x[0], f[2], f[3] });
					dist[f[2]][x[0]][f[3]] = (f[0] + x[1]);
					s.insert({ (f[0] + x[1]), x[0], f[2], f[3] });
				}
			}
		}

		if (f[3] == 0) {
			for (auto x : g[1][f[1]]) { //in edgs.
				f[3] = x[3];
				int val = dist[f[2]][x[0]][f[3]];
				if (val > (f[0] + x[1] + x[2])) {
					if (val != inf)
						s.erase({ val, x[0], f[2], f[3] });
					dist[f[2]][x[0]][f[3]] = (f[0] + x[1] + x[2]);
					s.insert({ (f[0] + x[1] + x[2]), x[0], f[2], f[3] });
				}
				f[3] = 0;
			}
		}
	}
	cout << -1;
}

• Subtask 1: 0 / 5
• Subtask 2: 0 / 11
• Subtask 3: 0 / 21
• Subtask 4: 0 / 63