제출 #224097

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
224097		oolimry	Olympic Bus (JOI20_ho_t4)	C++14	0 / 100	34 ms	4584 KiB

ho_t4

#include <bits/stdc++.h>

using namespace std;
long long inf = (1LL << 56LL);

typedef pair<long long, long long> ii;
vector<ii> adj[205];
vector<ii> adjR[205];
long long dis[205];
long long dis1[205];
long long disn[205];
long long dis1R[205];
long long disnR[205];

int n, m; 

long long dij(int s, int t){
	fill(dis, dis + (n+1), inf);
	
	priority_queue<ii, vector<ii>, greater<ii> > dtr; /// use greater<int>
	dtr.push(ii(0,s));
    dis[s] = 0;
    ///first is minpath, second is vertex
    while(!dtr.empty()){
        ii cur = dtr.top();
        dtr.pop();
        for(int j = 0;j < (int) adj[cur.second].size();j++){
            ii nei = adj[cur.second][j];
            if(nei.first + cur.first < dis[nei.second]){
                dis[nei.second] = nei.first + cur.first;	
                dtr.push(ii(dis[nei.second],nei.second));
            }
        }
    }
    return dis[t];
}

long long dijR(int s, int t){
	fill(dis, dis + (n+1), inf);
	
	priority_queue<ii, vector<ii>, greater<ii> > dtr; /// use greater<int>
	dtr.push(ii(0,s));
    dis[s] = 0;
    ///first is minpath, second is vertex
    while(!dtr.empty()){
        ii cur = dtr.top();
        dtr.pop();
        for(int j = 0;j < (int) adjR[cur.second].size();j++){
            ii nei = adjR[cur.second][j];
            if(nei.first + cur.first < dis[nei.second]){
                dis[nei.second] = nei.first + cur.first;
                dtr.push(ii(dis[nei.second],nei.second));
            }
        }
    }
    return dis[t];
}

struct edge{
	long long u, v, c, d;
};
vector<edge> edges;

void prin(long long ans){
	if(ans >= inf) ans = -1;
	cout << ans;
	exit(0);
}

void subtask1(){
	long long ans = dij(1, n)+ dij(n, 1);
	for(int i = 0;i < m;i++){
		for(int i = 1;i <= n;i++) adj[i].clear();
		
		long long res = 0;
		for(int j = 0;j < m;j++){
			edge e = edges[j];
			if(i == j){
				adj[e.v].push_back(ii(e.c,e.v));
				res += e.d;
			}
			else adj[e.u].push_back(ii(e.c,e.v));
		}
		ans = min(ans, dij(1,n) + dij(n,1) + res);
	}
	
	prin(ans);
}

int main(){
	//freopen("i.txt","r",stdin);
	ios_base::sync_with_stdio(false);
	cin.tie(0);
	
	cin >> n >> m;
	for(int i = 0;i < m;i++){
		long long u, v, c, d; cin >> u >> v >> c >> d;
		edges.push_back({u,v,c,d});
		adj[u].push_back(ii(c,v));
		adjR[v].push_back(ii(c,u));
	}
	
	//if(m <= 1000) subtask1();
	dij(1,n);
	for(int i = 1;i <= n;i++) dis1[i] = dis[i];
	
	dij(n,1);
	for(int i = 1;i <= n;i++) disn[i] = dis[i];
	
	dijR(1,n);
	for(int i = 1;i <= n;i++) dis1R[i] = dis[i];
	
	dijR(n,1);
	for(int i = 1;i <= n;i++) disnR[i] = dis[i];
	
	long long ans = dis1[n] + disn[1];
	for(edge e : edges){
		ans = min(ans, e.d + dis1[n] + disn[e.v] + dis1R[e.u] + e.c);
		ans = min(ans, e.d + disn[1] + dis1[e.v] + disnR[e.u] + e.c);
	}
	
	prin(ans);
}

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