Submission #47246

#	Time	Username	Problem	Language	Result	Execution time	Memory
47246		PowerOfNinjaGo	Cities (BOI16_cities)	C++17	100 / 100	2934 ms	70620 KiB

cities

//Power Of Ninja Go
#include <bits/stdc++.h>
//#ifdef atom #else #endif
using namespace std;
typedef long long ll; typedef pair<int, int> ii; typedef vector<int> vi; typedef vector< ii > vii;
#define X first
#define Y second
#define pb push_back
const int maxn = 1e5+5;
vii adj[maxn];
ll dp[32][maxn];
int main()
{
    int n, k, m; scanf("%d %d %d", &n, &k, &m);
    vi imp; imp.resize(k);
    for(int i = 0; i< k; i++) scanf("%d", &imp[i]);
    for(int i = 0; i< m; i++)
    {
        int u, v, w; scanf("%d %d %d", &u, &v, &w);
        adj[u].pb(ii(v, w));
        adj[v].pb(ii(u, w));
    }
    for(int a = 0; a< 32; a++)
    {
        for(int u = 1; u<= n; u++) dp[a][u] = 4e18;
    }
    for(int i = 0; i< k; i++)
    {
        dp[1<<i][imp[i]] = 0;
    }
    for(int bit = 1; bit< (1<<k); bit++)
    {
        for(int part = 0; part< bit; part++)
        {
            if((part | bit) != bit) continue;
            int rem = bit-part;
            for(int u = 1; u<= n; u++)
                dp[bit][u] = min(dp[bit][u], dp[part][u]+dp[rem][u]);
        }
        priority_queue< pair<ll, int> > pq;
        for(int i = 1; i<= n; i++)
        {
            if(dp[bit][i] != 4e18)
            {
                pq.push(make_pair(-dp[bit][i], i));
            }
        }
        while(!pq.empty())
        {
            ll w = -pq.top().X;
            int u = pq.top().Y;
            pq.pop();
            if(dp[bit][u] != w) continue;
            for(auto edge : adj[u])
            {
                int v = edge.X, w = edge.Y;
                if(dp[bit][v]> dp[bit][u]+w)
                {
                    dp[bit][v] = dp[bit][u]+w;
                    pq.push(make_pair(-dp[bit][v], v));
                }
            }
        }
    }
    ll res = 4e18;
    for(int i = 1; i<= n; i++) res = min(res, dp[(1<<k)-1][i]);
    cout << res << endl;
}

Compilation message (stderr)

cities.cpp: In function 'int main()':
cities.cpp:14:23: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     int n, k, m; scanf("%d %d %d", &n, &k, &m);
                  ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
cities.cpp:16:36: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     for(int i = 0; i< k; i++) scanf("%d", &imp[i]);
                               ~~~~~^~~~~~~~~~~~~~~
cities.cpp:19:27: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
         int u, v, w; scanf("%d %d %d", &u, &v, &w);
                      ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~

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