Submission #1130080

#	Time	Username	Problem	Language	Result	Execution time	Memory
1130080		am_aadvik	Olympic Bus (JOI20_ho_t4)	C++17	0 / 100	1094 ms	25928 KiB

ho_t4

#include <iostream>
#include<set>
#include<map>
#include<vector>
#define int long long
using namespace std;

vector<vector<int>> g[205][2];
map<vector<int>, int> dist;
vector<vector<int>> e;
int32_t main()
{
	ios_base::sync_with_stdio(false);
	cin.tie(NULL);

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

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

		if (f[1] == n) f[2] = 1; //1 way complete!
		for (auto x : g[f[1]][1]) { //in edgs.
			f[3] = x[3];
			if (dist.find({ x[0], f[2], f[3] }) != dist.end()) {
				if (dist[{ x[0], f[2], f[3] }] < (f[0] + x[1]))
					continue; //worse path 
				s.erase({ dist[{ x[0], f[2], f[3] }], x[0], f[2], f[3] });
			}
			dist[{ x[0], f[2], f[3] }] = (f[0] + x[1]);
			s.insert({ dist[{ x[0], f[2], f[3] }], x[0], f[2], f[3] });
			f[3] = 0;
		}

		if (f[3] == 0) {
			for (auto x : g[f[1]][1]) { //in edgs.
				f[3] = x[3];
				if (dist.find({ x[0], f[2], f[3] }) != dist.end()) {
					if (dist[{ x[0], f[2], f[3] }] < (f[0] + x[1] + x[2]))
						continue; //worse path 
					s.erase({ dist[{ x[0], f[2], f[3] }], x[0], f[2], f[3] });
				}
				dist[{ x[0], f[2], f[3] }] = (f[0] + x[1] + x[2]);
				s.insert({ dist[{ x[0], f[2], f[3] }], 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