Submission #1106235

#	Time	Username	Problem	Language	Result	Execution time	Memory
1106235		tradz	Cities (BOI16_cities)	C++14	100 / 100	1193 ms	105072 KiB

cities

#include <bits/stdc++.h>
#define TIME  (1.0 * clock() / CLOCKS_PER_SEC)
#define For(i,a,b) for(int i = a; i <= b; i++)
#define Ford(i,a,b) for(int i = a; i >= b; i--)
#define ll long long
#define ii pair<int,int>
#define fi first
#define se second
#define all(v) v.begin(),v.end()
#define RRH(v) v.resize(unique(all(v)) - v.begin())

using namespace std;
const int  N = 3e5+7;
const int M = 1e9+7;
const ll oo = 3e18;

mt19937_64 rng(chrono::steady_clock::now().time_since_epoch().count());

long long GetRandom(long long l, long long r) {
    return uniform_int_distribution<long long> (l, r)(rng);
}
int n, k, m, a[N];
vector<pair<int, ll>> g[N];
ll dist[33][N];

int main() {
    ios::sync_with_stdio(0); cin.tie(0);

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

    cin >> n >> k >> m;
    For (i, 1, k) {
        cin >> a[i];
    }

    For (i, 1, m) {
        int u, v, w;
        cin >> u >> v >> w;
        g[u].push_back({v, w});
        g[v].push_back({u, w});
    }

    For (j, 0, 32) For (i, 0, n) dist[j][i] = oo;
    For (i, 1, k) dist[(1 << (i - 1))][a[i]] = 0;

    priority_queue <pair<ll, int>, vector<pair<ll,int>>, greater<pair<ll,int>>> q;
    For (mask, 1, (1 << k) - 1) {
        for (int submask = mask; submask > 0; submask = (submask - 1) & mask) {
            For (i, 1, n) {
                dist[mask][i] = min(dist[mask][i], dist[submask][i] + dist[mask ^ submask][i]);
            }
        }

      //  cout << mask << '\n';

        for (int i = 1; i <= n; i++) {
            if (dist[mask][i] < oo) {
                q.push({dist[mask][i], i});
               // cout << i << " ";
            }
        }

        //cout << mask << '\n';

        while (!q.empty()) {
            ll d, u;
            tie(d, u) = q.top();
            q.pop();
            if (dist[mask][u] != d) continue;
            for (auto [v, w]: g[u]) {
                if (dist[mask][v] > d + w) {
                    dist[mask][v] = d + w;
                    q.push({d + w, v});
                }
            }
        }
    }

    ll ans = oo;

    For (i, 1, n) ans = min(ans, dist[(1 << k) - 1][i]);

    cout << ans << '\n';

    cerr << "Time elapsed: " << TIME << " s.\n";
    return 0;
}

Compilation message (stderr)

cities.cpp: In function 'int main()':
cities.cpp:78:23: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
   78 |             for (auto [v, w]: g[u]) {
      |                       ^
cities.cpp:31:17: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   31 |         freopen (".inp", "r", stdin);
      |         ~~~~~~~~^~~~~~~~~~~~~~~~~~~~
cities.cpp:32:17: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   32 |         freopen (".out", "w", stdout);
      |         ~~~~~~~~^~~~~~~~~~~~~~~~~~~~~
cities.cpp:35:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   35 |         freopen(TASK".inp", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
cities.cpp:36:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   36 |         freopen(TASK".out", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~

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