Submission #563114

#	Time	Username	Problem	Language	Result	Execution time	Memory
563114		Bobonbush	Cities (BOI16_cities)	C++17	100 / 100	2837 ms	45640 KiB

cities

#include <bits/stdc++.h>
#define foreach for
#define in :
using namespace std;
typedef long long ll;

/*
Konichiwa
Konichiwa
Ara ~~ ara

Bob no taisuki - Shinobu Kocho
    * * * * *
  *          *
 *         *
*         *        I love SHINOBU <3 <3 <3
 *         *
  *          *
    * * * * *
*/

/*
_________________________


    Author : Bob15324

_________________________
*/

template<class X , class Y>
    bool Minimize(X & x , Y y)
    {
        if((x == -1 || x > y) &&  (y >= 0))
        {
            x = y;
            return true;
        }
        return false;
    }

template<class X , class Y>
    bool Maximize(X & x , Y y)
    {
        if( x < y)
        {
            x = y;
            return true;
        }
        return false;
    }

/* End of templates. Let's see what do we have here */
const int N = 1e5+1;
const int K = 5;
int n , k , m;
int special[K];
long long dist[N] , dp[N][1 << K];


class GRAPH
{
    private:
        vector<vector<pair<int ,int >>>vertices;

    public:
        GRAPH(int _n)
        {
            vertices.resize(_n+1);
        }

        void AddEdge(int u ,int v ,int w)
        {
            vertices[u].push_back(make_pair(v , w));
            vertices[v].push_back(make_pair(u , w));
        }

        void Dijktra()
        {
            priority_queue<pair<long long , int > , vector<pair<long long , int>> , greater<pair<long long , int>>>pq;
            for(int i = 1; i <= n ; i++)
            {
                pq.push(make_pair(dist[i] , i));
            }
            while(!pq.empty())
            {
                pair<long long , int > temp = pq.top();
                pq.pop();
                int u = temp.second;
                long long du = temp.first;
                if(dist[u] < du)
                {
                    continue;
                }
                foreach(pair<int ,int > adj in vertices[u])
                {
                    int v = adj.first;
                    int w = adj.second;
                    if(Minimize(dist[v] , dist[u] + w))
                    {
                        pq.push(make_pair(dist[v] , v));
                    }
                }
            }
        }
};

int main()
{
    ios_base :: sync_with_stdio(0);cin.tie(0);
    cin >> n >> k >> m;
    for(int i = 1; i <= n ; i++)
    {
        dist[i] = 1e18+1;
        for(int j = 0 ; j <= (1 << k)-1 ; j++)
        {
            dp[i][j] = 1e18+1;
        }
    }
    for(int i = 0;  i< k ; i++)
    {
        cin >> special[i];
        dp[special[i]][1 << i] = 0;
    }
    GRAPH graph(n);
    for(int i = 1; i <= m ; i++)
    {
        int u , v , w;
        cin >> u >> v >> w;
        graph.AddEdge(u , v , w);
    }
    for(int mask = 0 ; mask <= (1 << k )-1 ; mask++)
    {
        for(int i = 0 ; i <= (1 << k)-1 ; i++ )
        {
            for(int j = 0 ; j <= (1 << k)-1 ; j++)
            {
                if((i | j) == mask)
                {
                    for(int z = 1 ; z <= n ; z++)
                    {
                        Minimize(dp[z][mask] , dp[z][i] + dp[z][j]);
                    }
                }
            }
        }

        for(int i = 1 ; i <= n ; i++)
        {
            dist[i] = dp[i][mask];
        }
        graph.Dijktra();
        for(int i = 1 ; i <= n ; i++)
        {
            dp[i][mask] = dist[i];
        }
    }
    long long res = -1;
    for(int i = 1; i <= n ; i++)
    {
        Minimize(res , dp[i][(1 << k)-1]);
    }
    cout << res;
    return 0;
}

//Ehem. My code is amazing. Pay me 2$.Thank you.

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