제출 #1167904

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
1167904		DangKhoizzzz	Commuter Pass (JOI18_commuter_pass)	C++20	31 / 100	170 ms	31080 KiB

commuter_pass

// chill roi

#include <bits/stdc++.h>
#define int long long
#define fi first
#define se second
#define pii pair <int , int>
#define arr3 array <int , 3>
#define arr4 array <int , 4>

/*
+ array limit ???
+ special case ??? n = 1?
+ time limit ???
*/

using namespace std;

const int INF = 1e18 + 7;
const int maxn = 2e5 + 7;

int n , m;
int S , T;
int U , V;

int ans = INF;

vector <pii> g[maxn];

vector <int> dijkstra(int start)
{
    vector <int> d(maxn , INF);
    vector <bool> vis(maxn , false);

    priority_queue <pii , vector <pii> , greater <pii>> PQ;
    d[start] = 0;
    PQ.push({0 , start});

    while(!PQ.empty())
    {
        int u = PQ.top().se;
        PQ.pop();
        if(vis[u]) continue;
        vis[u] = 1;

        for(pii edge: g[u])
        {
            int v = edge.fi;
            int w = edge.se;
            if(d[v] > d[u] + w)
            {
                d[v] = d[u] + w;
                PQ.push({d[v] , v});
            }
        }
    }
    return d;
}

void dijkstra2()
{
    vector <int> du = dijkstra(U);
    vector <int> dv = dijkstra(V);
    vector <bool> vis(maxn , false);
    vector <arr4> d(maxn , {INF,INF,INF});

    d[S] = {0 , du[S] , dv[S]};

    priority_queue <arr4 , vector <arr4> , greater <arr4>> PQ;
    PQ.push({0 , du[S] , dv[S] , S});

    while(!PQ.empty())
    {
        int u = PQ.top()[3];
        PQ.pop();
        if(vis[u]) continue;
        vis[u] = 1;

        for(pii edge: g[u])
        {
            int v = edge.fi;
            int w = edge.se;

            if(d[v][0] > d[u][0] + w)
            {
                d[v][0] = d[u][0] + w;
                d[v][1] = min(d[u][1] , du[v]);
                d[v][2] = min(d[u][2] , dv[v]);
                PQ.push({d[v][0] , d[v][1] , d[v][2] , v});
            }
            else if(d[v][0] == d[u][0] + w && d[v][1] + d[v][2] > d[u][1] + d[u][2])
            {
                d[v][1] = d[u][1];
                d[v][2] = d[u][2];
                PQ.push({d[v][0] , d[v][1] , d[v][2] , v});
            }
        }
    }

    cout << min(du[V] , d[T][1] + d[T][2]);
}

void solve()
{
    cin >> n >> m;
    cin >> S >> T;
    cin >> U >> V;
    for(int i = 1; i <= m; i++)
    {
        int u , v , w;
        cin >> u >> v >> w;
        g[u].push_back({v , w});
        g[v].push_back({u , w});
    }
    dijkstra2();
}

signed main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(0); cout.tie(0);
    solve();
    return 0;
}

• Subtask 1: 16 / 16
• Subtask 2: 15 / 15
• Subtask 3: 0 / 24
• Subtask 4: 0 / 45