Submission #682620

#	Time	Username	Problem	Language	Result	Execution time	Memory
682620		Ronin13	Cities (BOI16_cities)	C++14	100 / 100	2716 ms	48736 KiB

cities

#include <bits/stdc++.h>
#define ll long long
#define ull unsigned ll
#define f first
#define s second
#define pii pair<ll,ll>
#define pll pair<ll,ll>
#define pb push_back
#define epb emplace_back
using namespace std;
const int nmax =1e5 + 1;

const ll linf = 1e18 + 1;
ll d[nmax][32];
vector <vector <pll> > g(nmax);

int main(){
    int n; cin >> n;
    int k; cin >> k;
    int m; cin >> m;
    int imp[k + 1];
    for(int i= 1; i <= n; i++)
        for(int j = 0; j < 32; j++)
            d[i][j] = linf;
    for(int i = 1; i <= k; i++) {
        cin >> imp[i];
    }
    for(int i= 1; i <= m; i++){
        int u, v, len;
        cin >> u >> v >> len;
        g[u].epb(v, len);
        g[v].epb(u, len);
    }
    for(int i = 0; i < k; i++){
        d[imp[i + 1]][(1 << i)] = 0;
    }
    for(int mask = 1; mask < (1 << k); mask++){
        for(int submask = 1; submask < mask; submask++){
            if((mask | submask) != mask) continue;
            for(int j = 1; j <= n; j++)
                d[j][mask] = min(d[j][mask], d[j][submask] + d[j][mask ^ submask]);
        }
        priority_queue<pll> st;
        for(int i = 1; i <= n; ++i){
            if(d[i][mask] != linf)
                st.push({-d[i][mask], i});
        }
        vector <bool> used(n + 1);
        while(!st.empty()){
            int v = st.top().s;
            st.pop();
            if(used[v]) continue;
            used[v] = true;
            for(auto x : g[v]){
                int to = x.f;
                ll len = x.s;
                if(d[v][mask] + len < d[to][mask]){
                    d[to][mask] = d[v][mask] + len;
                    st.push({-d[to][mask], to});
                }
            }
        }
    }
    cout << d[imp[1]][(1 << k) - 1];
    return 0;
}

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