Submission #375721

#	Time	Username	Problem	Language	Result	Execution time	Memory
375721		iliccmarko	Commuter Pass (JOI18_commuter_pass)	C++14	100 / 100	446 ms	27084 KiB

commuter_pass

#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define endl "\n"
#define INF 1000000000
#define LINF 1000000000000000LL
#define pb push_back
#define all(x) x.begin(), x.end()
#define len(s) (int)s.size()
#define test_case { int t; cin>>t; while(t--)solve(); }
#define single_case solve();
#define line cerr<<"----------"<<endl;
#define ios { ios_base::sync_with_stdio(false); cin.tie(NULL); cout.tie(NULL); cerr.tie(NULL); }
#define mod 1000000007LL
int n, m, s, t, u, v;
const int N = 1e5 + 50;
vector<pair<int, ll> > g[N];
vector<int> dag[N];
ll dpu[N], dpv[N];
ll diss[N], disv[N], dist[N], disu[N];
int vidjen[N];

void dijkstra(int src, ll dis[])
{
    for(int i = 0;i<N;i++) dis[i] = LINF, vidjen[i] = 0;
    dis[src] = 0;
    priority_queue<pair<ll, ll>, vector<pair<ll, ll> >, greater<pair<ll, ll> > > pq;
    pq.push(make_pair(0, src));
    while(len(pq))
    {
        int u = pq.top().second;
        pq.pop();
        if(vidjen[u]) continue;
        vidjen[u] = 1;
        for(auto x : g[u])
        {
            if(dis[x.first]>dis[u]+x.second)
            {
                dis[x.first] = dis[u] + x.second;
                pq.push(make_pair(dis[x.first], x.first));
            }
        }
    }
}

ll dfs(int u, ll d[], ll dp[])
{
    dp[u] = d[u];
    vidjen[u] = 1;
    for(auto x : dag[u])
    {
        if(vidjen[x])
        {
            dp[u] = min(dp[u], dp[x]);
            continue;
        }
        dp[u] = min(dp[u], dfs(x, d, dp));
    }
    return dp[u];
}

int main()
{
    ios
    for(int i = 0;i<N;i++) dpu[i] = dpv[i] = LINF;
    cin>>n>>m>>s>>t>>u>>v;
    for(int i = 0;i<m;i++)
    {
        int a, b, c;
        cin>>a>>b>>c;
        g[a].pb(make_pair(b, c));
        g[b].pb(make_pair(a, c));
    }
    dijkstra(s, diss);
    dijkstra(t, dist);
    dijkstra(u, disu);
    dijkstra(v, disv);
    ll res = disu[v];
    for(int i = 1;i<=n;i++)
    {
        for(auto x : g[i])
        {
            if(diss[i]+x.second+dist[x.first]==diss[t])
            {
                dag[i].pb(x.first);
            }
        }
    }
    for(int i = 1;i<=n;i++) vidjen[i] = 0;
    dfs(s, disu, dpu);
    for(int i = 1;i<=n;i++)
    {
        res = min(res, dpu[i]+disv[i]);
    }
    for(int i = 1;i<=n;i++) vidjen[i] = 0;
    dfs(s, disv, dpv);
    for(int i = 1;i<=n;i++)
    {
        res = min(res, dpv[i]+disu[i]);
    }

    cout<<res;

    return 0;
}

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