제출 #440987

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
440987		ritul_kr_singh	Olympic Bus (JOI20_ho_t4)	C++17	37 / 100	1079 ms	4420 KiB

ho_t4

// #pragma GCC optimize("Ofast,unroll-loops")
#include <bits/stdc++.h>
using namespace std;
#define int long long
#define sp << ' ' <<
#define nl << '\n'

const int INF = 1e16;

int n, m, ans = INF;
priority_queue<array<int, 2>> q;
vector<array<int, 3>> g[2][200];

void dijkstra(int r, int s, vector<int> &d, int i){
	d.assign(n, INF);
	d[s] = 0;
	if(r == s) return;
	q.push({0, s});
	while(!q.empty()){
		int u = q.top()[1], dist = -q.top()[0]; q.pop();
		if(dist != d[u]) continue;
		for(auto &[v, w, t] : g[i][u])
			if(v != r && d[v] > dist + w)
				q.push({-(d[v] = dist + w), v});
	}
}

signed main(){
	cin.tie(0)->sync_with_stdio(0);
	cin >> n >> m;
	while(m--){
		int u, v, w, d; cin >> u >> v >> w >> d;
		--u, --v;
		g[0][u].push_back({v, w, d});
		g[1][v].push_back({u, w, d});
	}

	for(int u=0; u<n; ++u){
		vector<int> d[2], e[2];
		for(int i=0; i<2; ++i){
			dijkstra(u, i ? n-1 : 0, d[i], 0);
			dijkstra(u, i ? n-1 : 0, e[i], 1);
		}

		for(auto &[v, w, x] : g[1][u])
			for(int j=0; j<2; ++j)
				d[j][u] = min(d[j][u], w + d[j][v]);

		array<int, 2> x[2], y[2];
		for(int j=0; j<2; ++j) x[j] = y[j] = {INF, -1};

		for(int i=0; i<(int)g[0][u].size(); ++i){
			for(int j=0; j<2; ++j){
				y[j] = min(y[j], {e[j][g[0][u][i][0]] + g[0][u][i][1], i});
				if(x[j] > y[j]) swap(x[j], y[j]);
			}
		}
		if(u == 0) x[0][0] = y[0][0] = 0;
		if(u==n-1) x[1][0] = y[1][0] = 0;

		for(int i=0; i<(int)g[0][u].size(); ++i){
			auto &[v, w, t] = g[0][u][i];
			array<int, 2> uE;
			for(int j=0; j<2; ++j) uE[j] = x[j][1] == i ? y[j][0] : x[j][0];

			int a = d[0][v] + w + uE[1];
			int b = d[1][v] + w + uE[0];

			ans = min(ans, a + t + min(e[0][n-1], d[1][u] + uE[0]));
			ans = min(ans, b + t + min(e[1][0], uE[1] + d[0][u]));

			ans = min(ans, a + b + t);
		}
	}

	vector<int> d[2];
	dijkstra(-1, 0, d[0], 0);
	dijkstra(-1, n-1, d[1], 0);
	ans = min(ans, d[0][n-1] + d[1][0]);

	cout << (ans == INF ? -1 : ans) nl;
}

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