Submission #338155

#	Time	Username	Problem	Language	Result	Execution time	Memory
338155		KazamaHoang	Cities (BOI16_cities)	C++14	14 / 100	287 ms	26212 KiB

cities

/* -> Written by <-
   -----------
  K_A_Z_A_M_A
  ___________
      _    |
  |   (^_^)   |
  |  /( | )\  |
  |____|_|____|
    H O A N G
*/

#include <bits/stdc++.h>

#define Task            ""
#define F               first
#define S               second
#define pb              push_back
#define bit(x, i)       ((x >> (i)) & 1)
#define inf             1e9 + 7
#define INF             1e18 + 7
#define ll              long long
#define pii             pair <int, int>
#define debug(x)        cerr << #x << " is " << x << "\n";

using namespace std;

const int MOD = 1e9 + 7;
const int maxn = 1e5 + 5;

int n, k, m;
vector <pair<int, int>> ke[maxn];
int b[maxn];
ll d[4][maxn];

void ijk(int u, ll dis[]){
    priority_queue <pair<ll, int>> pq;
    fill(dis + 1, dis + 1 + n, INF);
    dis[u] = 0;
    pq.push({0, u});
    while (!pq.empty()){
        int u = pq.top().S;
        ll l = - pq.top().F;
        pq.pop();
        if (l > dis[u]) continue;
        for (auto p : ke[u]){
            int v = p.F;
            int w = p.S;
            if (dis[v] > dis[u] + w){
                dis[v] = dis[u] + w;
                pq.push({-dis[v], v});
            }
        }
    }
}

void Solve(){
    cin >> n >> k >> m;
    for (int i = 1; i <= k; ++ i){
        cin >> b[i];
    }
    for (int i = 1; i <= m; ++ i){
        int u, v, w;
        cin >> u >> v >> w;
        ke[u].pb({v, w});
        ke[v].pb({u, w});
    }
    for (int i = 1; i <= k; ++ i){
        ijk(b[i], d[i]);
    }
    ll res = INF;
    for (int i = 1; i <= n; ++ i){
        ll cur = 0;
        for (int j = 1; j <= k; ++ j){
            cur += d[j][i];
        }
        res = min(res, cur);
    }
    cout << res;
}

int main(){
    ios_base::sync_with_stdio(false);cin.tie(NULL);cout.tie(NULL);
    if(fopen(Task".inp", "r")){
        freopen(Task".inp","r",stdin);
        freopen(Task".out","w",stdout);
    }
    int test_case = 1;
//     cin >> test_case;
    while (test_case --){
        Solve();
    }

    return 0;
}

Compilation message (stderr)

cities.cpp: In function 'int main()':
cities.cpp:84:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result]
   84 |         freopen(Task".inp","r",stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~
cities.cpp:85:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result]
   85 |         freopen(Task".out","w",stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~

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