Submission #869399

#	Time	Username	Problem	Language	Result	Execution time	Memory
869399		vjudge1	Commuter Pass (JOI18_commuter_pass)	C++17	0 / 100	314 ms	34480 KiB

commuter_pass

//In His Name
#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define int ll
typedef pair<int, int> pii;
typedef pair<long long, int> pli;
typedef pair<long long, long long> pll;
#define F first
#define S second
#define pb push_back
#define bug(x) cout << "Ah shit , here we go again : " << x <<endl
#define all(x) x.begin() , x.end()
#define ceil(x,y) x/y + min(1ll,x%y)
const int maxn = 2e5 + 10, MOD = 1e9 + 7;
const ll INF = 1e18;

int n , m , s , t , u , v  , dis[maxn];
vector<pli> adj[maxn];
vector<int>  par[maxn];
set<int> path;
bool mark[maxn];

void dijkstra(int root){
    fill(dis , dis+n+1 , INF);
    dis[root] = 0;
    set<pli> st;
    st.insert({0,root});
    while(!st.empty()){
        int a = (*st.begin()).S;
        st.erase(st.begin());
        for(pii i : adj[a]){
            if(dis[i.S] >= dis[a] + i.F){
                st.erase({dis[i.S] , i.S});
                dis[i.S] = dis[a] + i.F;
                st.insert({dis[i.S] , i.S});
                par[i.S].pb(a);
            }
        }
    }
}

signed main(){
    ios_base::sync_with_stdio(false);
    cin >> n >> m >> s >> t >> u >> v;
    for(int i = 1 ; i <= m ; i ++){
        int a , b , w;
        cin >> a >> b  >> w;
        adj[a].pb({w , b});
        adj[b].pb({w , a});
    }
    dijkstra(s);
    queue<int> q;
    q.push(t);
    while(!q.empty()){
        if(mark[q.front()]){
            q.pop();
            continue;
        }
        mark[q.front()] = true;
        for(int i : par[q.front()]){
            path.insert(i);
            if(!mark[i]) q.push(i);
        }
        q.pop();
    }
    int ans = dis[v];
    dijkstra(v);
    for(int i : path) ans = min(ans, dis[i]);
    cout << ans;
}

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