Submission #975896

#	Time	Username	Problem	Language	Result	Execution time	Memory
975896		Nipphitch	Cities (BOI16_cities)	C++11	100 / 100	1944 ms	54216 KiB

cities

#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define pii pair <ll,int>
#define f first
#define s second
const int N=1e5+5;
const int K=40;
const ll INF=LLONG_MAX/2;

int n,k,m;
ll dp[K][N];
vector <pii> adj[N];
priority_queue <pii,vector<pii>,greater<pii>> pq;

int main()
{
    ios::sync_with_stdio(0);
    cin.tie(0);
    fill_n(dp[0],K*N,INF);
    cin >> n >> k >> m;
    for(int i=0;i<k;i++){
        int x;
        cin >> x;
        dp[(1<<i)][x]=0;
    }
    for(int i=0;i<m;i++){
        int u,v,w;
        cin >> u >> v >> w;
        adj[u].push_back({v,w});
        adj[v].push_back({u,w});
    }
    for(int mask1=1;mask1<(1<<k);mask1++){
        for(int mask2=1;mask2<mask1;mask2++){
            if(mask1&mask2){
                for(int i=1;i<=n;i++){
                    dp[mask1][i]=min(dp[mask1][i],dp[mask2][i]+dp[mask1^mask2][i]);
                }
            }
        }
        for(int i=1;i<=n;i++) if(dp[mask1][i]!=INF) pq.push({dp[mask1][i],i});
        while(!pq.empty()){
            auto [d_u,u]=pq.top();
            pq.pop();
            for(auto [v,w]:adj[u]){
                if(dp[mask1][v]>d_u+w) pq.push({dp[mask1][v]=d_u+w,v});
            }
        }
    }
    cout << *min_element(dp[(1<<k)-1]+1,dp[(1<<k)-1]+n+1);
}

Compilation message (stderr)

cities.cpp: In function 'int main()':
cities.cpp:43:18: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
   43 |             auto [d_u,u]=pq.top();
      |                  ^
cities.cpp:45:22: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
   45 |             for(auto [v,w]:adj[u]){
      |                      ^

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