Submission #647336

#	Time	Username	Problem	Language	Result	Execution time	Memory
647336		fatemetmhr	Cities (BOI16_cities)	C++17	100 / 100	2259 ms	38100 KiB

cities

//  ~ Be Name Khoda ~  //

#include<bits/stdc++.h>

using namespace std;

typedef long long ll;

#define pb       push_back
#define mp       make_pair
#define all(x)   x.begin(), x.end()
#define fi       first
#define se       second

const int maxn  =  1e6   + 10;
const int maxn5 =  1e5   + 10;
const int maxnt =  1.2e6 + 10;
const int maxn3 =  1e3   + 10;
const int mod   =  1e9   +  7;
const ll  inf   =  1e18;

vector <pair<int, int>> adj[maxn5];
ll dp[(1 << 5) + 1][maxn5];
int imp[maxn5], cmpmask, n;
priority_queue <pair<ll, int>> av;

inline void dij(int mask){
    while(av.size())
        av.pop();
    for(int i = 0; i < n; i++)
        av.push({-dp[mask][i], i});
    while(av.size()){
        while(av.size() && dp[mask][av.top().se] != av.top().fi * -1)
            av.pop();
        if(av.empty())
            return;
        int v = av.top().se; av.pop();
        for(auto [u, w] : adj[v]) if(dp[mask][u] > dp[mask][v] + w){
            dp[mask][u] = dp[mask][v] + w;
            av.push({-dp[mask][u], u});
        }
    }
    return;
}

int main()
{
    ios_base::sync_with_stdio(false);cin.tie(0);cout.tie(0);

    int k, m; cin >> n >> k >> m;
    for(int i = 0; i < k; i++){
        cin >> imp[i];
        imp[i]--;
    }
    for(int i = 0; i < m; i++){
        int a, b, c; cin >> a >> b >> c;
        a--; b--;
        if(a == b)
            continue;
        adj[a].pb({b, c});
        adj[b].pb({a, c});
    }

    for(int mask = 0; mask < (1 << k); mask++) for(int i = 0; i < n; i++)
        dp[mask][i] = inf;

    for(int i = 0; i < n; i++)
        dp[0][i] = 0;

    for(int i = 0; i < k; i++){
        dp[1 << i][imp[i]] = 0;
        for(auto [u, w] : adj[imp[i]])
            dp[1 << i][u] = min(dp[1 << i][u], ll(w));
    }

    for(int mask = 0; mask < (1 << k); mask++){
        dij(mask);
        for(int v = 0; v < n; v++){
            int nmask = (1 << k) - 1 - mask;
            for(int sub = nmask; sub; sub = (sub - 1) & nmask){
                dp[mask^sub][v] = min(dp[mask^sub][v], dp[mask][v] + dp[sub][v]);
            }
        }
    }

    ll ans = inf;
    for(int i = 0; i < n; i++)
        ans = min(ans, dp[(1 << k) - 1][i]);
    cout << ans << endl;
}


/*
8 3 9
2 8 7 
2 4 3
2 6 9
3 7 2
4 6 5
5 8 1
6 8 2
1 2 5
1 3 3
4 5 2
*/

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