Submission #1029278

#	Time	Username	Problem	Language	Result	Execution time	Memory
1029278		Neco_arc	Cities (BOI16_cities)	C++17	100 / 100	1400 ms	74048 KiB

cities

#include <bits/stdc++.h>
#ifdef LOCAL
#include <bits/debug.hpp>
#endif // LOCAL

#define ll long long
#define all(x) x.begin(), x.end()
#define Neco "City"
#define resp(x) sort(all(x)), x.resize(unique(all(x)) - x.begin())
#define getbit(x,i) ((x >> i)&1)
#define _left id * 2, l, mid
#define _right id * 2 + 1, mid + 1, r
#define cntbit(x) __builtin_popcountll(x)
#define fi(i, a, b) for(int i = a; i <= b; i++)
#define fid(i, a, b) for(int i = a; i >= b; i--)
#define maxn (int) 2e5 + 7

using namespace std;

const ll mod = 1e9 + 7; //972663749
const ll base = 911382323;

/// dp[u][x] la trong so cua cay nho nhat sao cho u va cac dinh thuoc x lien thong

int n, k, m;
int spe[maxn];
ll dp[(1 << 5) + 1][maxn];
vector<pair<int, int>> edges[maxn];

void DJK(ll *dist) {
    priority_queue<pair<ll, int>, vector<pair<ll, int>>, greater<pair<ll, int>> > q;
    fi(i, 1, n) q.push({dist[i], i});

    while(!q.empty()) {
        int u = q.top().second, g = q.top().first;
        q.pop();
        if(g > dist[u]) continue;

        for(auto [v, w] : edges[u]) if(dist[v] > dist[u] + w) {
            dist[v] = dist[u] + w;
            q.push({dist[v], v});
        }
    }

}

void solve()
{

    cin >> n >> k >> m;
    fi(i, 1, k) cin >> spe[i];
    fi(i, 1, m) {
        int x, y, w; cin >> x >> y >> w;
        edges[x].push_back({y, w}), edges[y].push_back({x, w});
    }

    memset(dp, 60, sizeof dp);

    fi(i, 1, k) {
        int u = spe[i];
        dp[(1 << (i - 1))][u] = 0;
    }

    fi(x, 1, (1 << k) - 1) {

        fi(u, 1, n) for(int y = x; y > 0; y = (y - 1) & x) {
            dp[x][u] = min(dp[x][u], dp[x ^ y][u] + dp[y][u]); /// gop 2 cau truc cay co chung goc la u
        }

        /// tu 1 cau truc cay toi uu loang sang cac dinh ko thuoc cay nay
        DJK(dp[x]);
    }

    ll ans = 1e18;
    fi(i, 1, n) ans = min(ans, dp[(1 << k) - 1][i]);

    cout << ans;

}


int main()
{

    ios_base::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);

    if(fopen(Neco".inp", "r")) {
        freopen(Neco".inp", "r", stdin);
        freopen(Neco".out", "w", stdout);
    }


    int nTest = 1;
//    cin >> nTest;


    while(nTest--)
    {
        solve();
    }


    return 0;
}

Compilation message (stderr)

cities.cpp: In function 'int main()':
cities.cpp:90:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   90 |         freopen(Neco".inp", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
cities.cpp:91:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   91 |         freopen(Neco".out", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~

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