Submission #1073218

#	Time	Username	Problem	Language	Result	Execution time	Memory
1073218		Jarif_Rahman	Cities (BOI16_cities)	C++17	100 / 100	1381 ms	48424 KiB

cities

#include <bits/stdc++.h>
#define pb push_back
#define f first
#define sc second
using namespace std;
typedef long long int ll;
typedef string str;

const ll inf = 1e18;
const int N = 1e5;

bitset<N> bl;
void dijkstra(int n, vector<pair<int, ll>> *graph, ll* dis){
    bl.reset();
    priority_queue<pair<ll, int>> pq;
    for(int s = 0; s < n; s++) if(dis[s] < inf) pq.push({-dis[s], s});
    
    while(!pq.empty()){
        int nd = pq.top().second;
        pq.pop();
        if(bl[nd]) continue;
        bl[nd] = 1;
        for(auto [x, w]: graph[nd]) if(dis[nd]+w < dis[x]){
            dis[x] = dis[nd]+w;
            pq.push({-dis[x], x});
        }
    }
}

int n, m, k;
vector<pair<int, ll>> graph[N];
vector<int> ic;
ll dis[32][N];

int main(){
    ios_base::sync_with_stdio(0);
    cin.tie(0);

    cin >> n >> k >> m;

    ic.resize(k);
    for(int &x: ic) cin >> x, x--;

    for(int i = 0; i < m; i++){
        int a, b; ll w; cin >> a >> b >> w; a--, b--;
        graph[a].push_back({b, w});
        graph[b].push_back({a, w});
    }

    for(int i = 0; i < k; i++){
        fill(dis[1<<i], dis[1<<i]+n, inf);
        dis[1<<i][ic[i]] = 0;
        dijkstra(n, graph, dis[1<<i]);
    }

    for(int mask = 1; mask < (1<<k); mask++){
        if(__builtin_popcount(mask) < 2) continue;
        fill(dis[mask], dis[mask]+n, inf);
        for(int submask = (mask-1)&mask; submask > 0; submask = (submask-1)&mask){
            for(int i = 0; i < n; i++)
                dis[mask][i] = min(dis[mask][i], dis[submask][i]+dis[mask^submask][i]);
        }
        dijkstra(n, graph, dis[mask]);
    }

    cout << *min_element(dis[(1<<k)-1], dis[(1<<k)-1]+n) << "\n";
}

• Subtask 1: 22 / 22
• Subtask 2: 14 / 14
• Subtask 3: 15 / 15
• Subtask 4: 23 / 23
• Subtask 5: 26 / 26