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Submission #375857

# Submission time Handle Problem Language Result Execution time Memory
375857 2021-03-10T05:25:38 Z danielcm585 Cities (BOI16_cities) C++14
100 / 100
 3458 ms 50760 KB 
#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
22.0 / 22.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 2668 KB Output is correct
2 Correct 2 ms 2668 KB Output is correct
3 Correct 2 ms 2668 KB Output is correct
4 Correct 2 ms 2668 KB Output is correct
5 Correct 2 ms 2668 KB Output is correct

Subtask #2
14.0 / 14.0

# Verdict Execution time Memory Grader output
1 Correct 887 ms 50520 KB Output is correct
2 Correct 876 ms 50112 KB Output is correct
3 Correct 550 ms 40368 KB Output is correct
4 Correct 86 ms 15448 KB Output is correct
5 Correct 460 ms 50400 KB Output is correct
6 Correct 79 ms 15504 KB Output is correct
7 Correct 5 ms 3180 KB Output is correct
8 Correct 4 ms 3308 KB Output is correct

Subtask #3
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 8 ms 3180 KB Output is correct
2 Correct 8 ms 3180 KB Output is correct
3 Correct 6 ms 3052 KB Output is correct
4 Correct 5 ms 3052 KB Output is correct

Subtask #4
23.0 / 23.0

# Verdict Execution time Memory Grader output
1 Correct 1739 ms 50516 KB Output is correct
2 Correct 1732 ms 50340 KB Output is correct
3 Correct 1132 ms 40588 KB Output is correct
4 Correct 961 ms 34388 KB Output is correct
5 Correct 216 ms 19756 KB Output is correct
6 Correct 91 ms 17748 KB Output is correct

Subtask #5
26.0 / 26.0

# Verdict Execution time Memory Grader output
1 Correct 3458 ms 50700 KB Output is correct
2 Correct 3447 ms 50760 KB Output is correct
3 Correct 3380 ms 50056 KB Output is correct
4 Correct 2311 ms 40700 KB Output is correct
5 Correct 1845 ms 34784 KB Output is correct
6 Correct 344 ms 19864 KB Output is correct
7 Correct 109 ms 17916 KB Output is correct