Submission #1082404

#	Time	Username	Problem	Language	Result	Execution time	Memory
1082404		dwuy	Cities (BOI16_cities)	C++14	100 / 100	1987 ms	50252 KiB

cities

#include <bits/stdc++.h>
#define MASK(x) (1LL<<(x))
using namespace std;
typedef long long ll;

const int MX = 100005;
int n, k, m;
int city[5];
ll f[MASK(5)][MX];
vector<pair<int, ll>> G[MX];

void nhap(){
    cin >> n >> k >> m;
    for(int i=0; i<k; i++) cin >> city[i];
    for(int i=1; i<=m; i++){
        int u, v, c;
        cin >> u >> v >> c;
        G[u].push_back({v, c});
        G[v].push_back({u, c});
    }
}

void solve(){
    memset(f, 0x3f, sizeof f);
    for(int mask=1; mask<MASK(k); mask++){
        if(mask-(-mask&mask) == 0){
            f[mask][city[__lg(mask)]] = 0;
        }
        else for(int Mask=mask; Mask>0; Mask=(Mask - 1)&mask){
            for(int i=1; i<=n; i++){
                f[mask][i] = min(f[mask][i], f[Mask][i] + f[mask^Mask][i]);
            }
        }
        priority_queue<pair<ll, int>, vector<pair<ll, int>>, greater<pair<ll, int>>> Q;
        for(int i=1; i<=n; i++) if(f[mask][i] != f[0][0]){
            Q.push({0, i});
        }
        while(Q.size()){
            int u; ll du;
            tie(du, u) = Q.top();
            Q.pop();
            for(pair<int, ll> edge: G[u]){
                int v; ll c;
                tie(v, c) = edge;
                if(f[mask][v] > f[mask][u] + c){
                    f[mask][v] = f[mask][u] + c;
                    Q.push({f[mask][v], v});
                }
            }
        }
    }
    ll ans = f[0][0];
    for(int i=1; i<=n; i++) ans = min(ans, f[MASK(k)-1][i]);
    cout << ans;
}

int32_t main(){
    ios_base::sync_with_stdio(false);
    cin.tie(0); cout.tie(0);

    nhap();
    solve();

    return 0;
}

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