Submission #337886

#	Time	Username	Problem	Language	Result	Execution time	Memory
337886		KazamaHoang	Cities (BOI16_cities)	C++14	0 / 100	91 ms	9964 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;
bool dd[maxn];
vector <int> ke[maxn];

struct DATA{
    int u, v, w;
}e[maxn * 2];

bool comp(DATA p, DATA q){
    return p.w < q.w;
}

int root[maxn];

int Get_Root(int u){
    if (root[u] != u) root[u] = Get_Root(root[u]);
    return root[u];
}

void Solve(){
    cin >> n >> k >> m;
    for (int i = 1; i <= k; ++ i){
        int x;
        cin >> x;
        dd[x] = 1;
    }
    for (int i = 1; i <= m; ++ i){
        int u, v, w;
        cin >> u >> v >> w;
        e[i] = {u, v, w};
    }
    sort(e + 1, e + 1 + m, comp);
    for (int i = 1; i <= n; ++ i) root[i] = i;
    int res = 0;
    for (int i = 1; i <= m; ++ i){
        int u = e[i].u;
        int v = e[i].v;
        int w = e[i].w;
        if (!dd[u] && !dd[v]) continue;
        u = Get_Root(u);
        v = Get_Root(v);
        if (u == v) continue;
        root[u] = v;
        res += w;
    }
    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:81:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result]
   81 |         freopen(Task".inp","r",stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~
cities.cpp:82:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result]
   82 |         freopen(Task".out","w",stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~

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