Submission #96252

#	Time	Username	Problem	Language	Result	Execution time	Memory
96252		easrui	Cities (BOI16_cities)	C++14	100 / 100	2264 ms	42396 KiB

cities

#include <bits/stdc++.h>
#define va first
#define vb second
using namespace std;
typedef long long ll;
typedef pair<ll,ll> pii;
const int MN = 1e5+5;
long long N,K,M,A,B,d,sz,Im[5],cur,tmp,cost,ans,D[32][MN];
vector<pii> G[MN];
priority_queue<pii> Q;
int main()
{
    ios_base::sync_with_stdio(0),cin.tie(0);
    cin >> N >> K >> M;
    for(int i=0; i<K; i++) cin >> Im[i];
    for(int i=0; i<M; i++){
        cin >> A >> B >> d;
        G[A].push_back(pii(B,d));
        G[B].push_back(pii(A,d));
    }
    sz = 1<<K;
    for(int i=0; i<sz; i++)
        for(int j=1; j<=N; j++) D[i][j] = 1e18;
    for(int j=0; j<K; j++) D[(1<<j)][Im[j]] = 0;
    for(int i=1; i<sz; i++){
        for(int j=1; j<=N; j++){
            tmp = 1e18;
            for(int p=1; p<sz/2; p++){
                if((p&i)!=p) continue;
                tmp = min(tmp,D[i-p][j] + D[p][j]);
            }
            D[i][j] = min(D[i][j],tmp);
            Q.emplace(-D[i][j],j);
        }
        while(!Q.empty()){
            cur = Q.top().vb;
            cost = -Q.top().va;
            Q.pop();
            if(cost>D[i][cur]) continue;
            for(pii x : G[cur]){
                if(D[i][x.va] > cost + x.vb){
                    D[i][x.va] = cost + x.vb;
                    Q.emplace(-D[i][x.va],x.va);
                }
            }
        }
    }
    ans = 1e18;
    for(int j=1; j<=N; j++) ans = min(ans,D[sz-1][j]);
    cout << ans;
}

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