Submission #1247656

#	Time	Username	Problem	Language	Result	Execution time	Memory
1247656		hainam2k9	Cities (BOI16_cities)	C++20	14 / 100	187 ms	44332 KiB

cities

#include <bits/stdc++.h>
#define tt cin.tie(0), cout.tie(0), ios_base::sync_with_stdio(0)
#define fo freopen((NAME+".INP").c_str(), "r", stdin), freopen((NAME+".OUT").c_str(), "w", stdout)
#define ll long long
#define ull unsigned long long
#define i128 __int128
#define db long double
#define sz(a) ((int)(a).size())
#define pb emplace_back
#define pf emplace_front
#define pob pop_back
#define pof pop_front
#define lb lower_bound
#define ub upper_bound
#define fi first
#define se second
#define ins emplace
#define mp make_pair
using namespace std;
const int MOD = 1e9+7, MAXN = 1e5+5;
const string NAME = "";
int n,k,m,a[10];
ll dist[10][MAXN],dp[35][MAXN],rs=1e18;
vector<pair<int,int>> adj[MAXN];
void dijkstra(ll dist[MAXN], int u){
    priority_queue<pair<ll,int>, vector<pair<ll,int>>, greater<pair<ll,int>>> pq;
    dist[u]=0, pq.ins(0,u);
    while(!pq.empty()){
        pair<ll,int> top = pq.top();
        pq.pop();
        if(top.fi>dist[top.se]) continue;
        for(pair<int,int>& e : adj[top.se])
            if(dist[e.fi]>top.fi+e.se) dist[e.fi]=top.fi+e.se, pq.ins(dist[e.fi],e.fi);
    }
}
int main()
{
    tt;
    if(fopen((NAME + ".INP").c_str(), "r")) fo;
    cin >> n >> k >> m;
    for(int i = 0; i<k; ++i)
        cin >> a[i];
    for(int i = 1; i<=m; ++i){
        int x,y,z;
        cin >> x >> y >> z;
        adj[x].pb(y,z), adj[y].pb(x,z);
    }
    memset(dist,0x3f,sizeof(dist));
    for(int i = 0; i<k; ++i)
        dijkstra(dist[i],a[i]);
    memset(dp,0x3f,sizeof(dp));
    for(int i = 1; i<=n; ++i)
        dp[0][i]=0;
    for(int mask = 1; mask<(1<<k); ++mask)
        for(int i = 0; i<k; ++i)
            if((mask>>i)&1)
                for(int j = 1; j<=n; ++j)
                    dp[mask][j]=min(dp[mask][j],dp[mask^(1<<i)][j]+dist[i][j]);
    for(int i = 1; i<=n; ++i)
        rs=min(rs,dp[(1<<k)-1][i]);
    cout << rs;
}

Compilation message (stderr)

cities.cpp: In function 'int main()':
cities.cpp:3:19: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
    3 | #define fo freopen((NAME+".INP").c_str(), "r", stdin), freopen((NAME+".OUT").c_str(), "w", stdout)
      |            ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
cities.cpp:39:45: note: in expansion of macro 'fo'
   39 |     if(fopen((NAME + ".INP").c_str(), "r")) fo;
      |                                             ^~
cities.cpp:3:63: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
    3 | #define fo freopen((NAME+".INP").c_str(), "r", stdin), freopen((NAME+".OUT").c_str(), "w", stdout)
      |                                                        ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
cities.cpp:39:45: note: in expansion of macro 'fo'
   39 |     if(fopen((NAME + ".INP").c_str(), "r")) fo;
      |                                             ^~

• Subtask 1: 0 / 22
• Subtask 2: 14 / 14
• Subtask 3: 0 / 15
• Subtask 4: 0 / 23
• Subtask 5: 0 / 26