제출 #375857

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
375857		danielcm585	Cities (BOI16_cities)	C++14	100 / 100	3458 ms	50760 KiB

cities

#include <bits/stdc++.h>
using namespace std;

#define fi first
#define se second

typedef long long ll;
typedef pair<ll,int> ii;

const int N = 1e5;
const int K = 5;
const int MX = (1<<K);
const ll INF = 1e18;
int n, m, k;
int s[K+2];
ll dp[N+2][MX+2];
vector<ii> adj[N+2];

void djikstra(int mask) {
    priority_queue<ii,vector<ii>,greater<ii>> pq;
    for (int i = 0; i < n; i++) pq.push({dp[i][mask],i});
    while (!pq.empty()) {
        ii cur = pq.top(); pq.pop();
        if (dp[cur.se][mask] != cur.fi) continue;
        for (auto i : adj[cur.se]) {
            ii nx = {cur.fi+i.se,i.fi};
            if (dp[nx.se][mask] > nx.fi) {
                dp[nx.se][mask] = nx.fi;
                pq.push(nx);
            }
        }
    }
}

int main() {
    ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
    cin >> n >> k >> m;
    for (int i = 0; i < k; i++) {
        cin >> s[i]; s[i]--;
    }
    for (int i = 0; i < m; i++) {
        int u, v, w; cin >> u >> v >> w;
        u--, v--;
        adj[u].push_back({v,w});
        adj[v].push_back({u,w});
    }
    for (int i = 0; i < n; i++) {
        for (int j = 0; j < (1<<k); j++) {
            dp[i][j] = INF;
        }
    }
    for (int mask = 1; mask < (1<<k); mask++) {
        if (__builtin_popcount(mask) == 1) {
            for (int i = 0; i < k; i++) {
                if ((mask>>i)&1) dp[s[i]][mask] = 0;
            }
        }
        for (int i = 0; i < k; i++) {
            if ((mask>>i)&1) {
                for (int j = 0; j < n; j++) {
                    dp[j][mask] = min(dp[j][mask],dp[j][1<<i]+dp[j][mask^(1<<i)]);
                }
            }
        }
        djikstra(mask);
    }
    ll ans = INF;
    for (int i = 0; i < n; i++) {
        ans = min(ans,dp[i][(1<<k)-1]);
    }
    cout << ans << '\n';
    return 0;
}

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