Submission #879558

#	Time	Username	Problem	Language	Result	Execution time	Memory
879558		Shayan86	Cities (BOI16_cities)	C++14	100 / 100	1556 ms	45316 KiB

cities

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

#pragma GCC optimize("O3,unroll-loops")
// #pragma GCC target("avx2,bmi,bmi2,lzcnt,popcnt")
// Ofast, O0, O1, O2, O3, unroll-loops, fast-math, trapv

typedef long long ll;
typedef pair<ll, ll> pll;
typedef pair<int, int> pii;

#define Mp          make_pair
#define sep         ' '
#define endl        '\n'
#define F	        first
#define S	        second
#define pb          push_back
#define all(x)      (x).begin(),(x).end()
#define kill(res)	cout << res << '\n', exit(0);
#define set_dec(x)	cout << fixed << setprecision(x);
#define fast_io     ios_base::sync_with_stdio(false);cin.tie(0);cout.tie(0);
#define file_io     freopen("input.txt", "r", stdin) ; freopen("output.txt", "w", stdout);

mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());

const ll K = 5;
const ll N = 1e5 + 50;
const ll inf = 1e18;

ll n, m, k, dist[(1 << K)][N];

bool mark[N];
vector<int> vec;
vector<pii> adj[N];

void dijk(int id){
    fill(mark, mark + N, 0);
    priority_queue<pll, vector<pll>, greater<pll>> pq;
    for(int i = 1; i <= n; i++) if(dist[id][i] < inf) pq.push({dist[id][i], i});

    while(!pq.empty()){
        int v = pq.top().S;
        pq.pop();

        if(mark[v]) continue;
        mark[v] = true;

        for(auto [u, w]: adj[v]){
            if(dist[id][v] + w < dist[id][u]){
                dist[id][u] = dist[id][v] + w;
                pq.push({dist[id][u], u});
            }
        }
    }
}

int main(){
    fast_io;

    cin >> n >> k >> m;

    int u, v, w;
    for(int i = 1; i <= k; i++){
        cin >> v; vec.pb(v);
    }

    for(int i = 1; i <= m; i++){
        cin >> u >> v >> w;
        adj[u].pb(Mp(v, w));
        adj[v].pb(Mp(u, w));
    }

    for(int i = 0; i < (1 << k); i++) fill(dist[i], dist[i] + N, inf);
    for(int i = 0; i < k; i++) dist[(1 << i)][vec[i]] = 0;

    for(int mask = 1; mask < (1 << k); mask++){
        for(int i = 1; i <= n; i++){
            for(int sub = mask; sub; sub = (sub-1) & mask){
                dist[mask][i] = min(dist[mask][i], dist[sub][i] + dist[mask ^ sub][i]);
            }
        }
        dijk(mask);
    }

    cout << dist[(1 << k)-1][vec[0]];

}

Compilation message (stderr)

cities.cpp: In function 'void dijk(int)':
cities.cpp:48:18: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
   48 |         for(auto [u, w]: adj[v]){
      |                  ^

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