Submission #338131

#	Time	Username	Problem	Language	Result	Execution time	Memory
338131		KazamaHoang	Cities (BOI16_cities)	C++14	0 / 100	251 ms	17132 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];
pair <int, pair<int, int>> e[maxn];
bool dd[maxn];
int b[maxn];

int root[21];

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

int Cal(int mask){
    for (int i = 1; i <= n; ++ i) root[i] = i;
    int cnt = 0, res = 0;
    for (int i = 1; i <= m; ++ i){
        int u = e[i].S.F;
        int v = e[i].S.S;
        int w = e[i].F;
        if (bit(mask, u-1) && bit(mask, v-1)){
            u = Get_Root(u);
            v = Get_Root(v);
            if (u == v) continue;
            root[u] = v;
            res += w;
        }
    }
    for (int i = 1; i < k; ++ i){
        int u = Get_Root(b[i]);
        for (int j = i + 1; j <= k; ++ j){
            int v = Get_Root(b[j]);
            if (u != v) return inf;
        }
    }
    return res;
}

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});
        e[i] = {w, {u, v}};
    }
    sort(e + 1, e + 1 + m);
    int ans = inf;
    for (int mask = 0; mask < (1 << n); ++ mask)
        ans = min(ans, Cal(mask));
    cout << ans;
}

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 Cal(int)':
cities.cpp:45:9: warning: unused variable 'cnt' [-Wunused-variable]
   45 |     int cnt = 0, res = 0;
      |         ^~~
cities.cpp: In function 'int main()':
cities.cpp:90:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result]
   90 |         freopen(Task".inp","r",stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~
cities.cpp:91:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result]
   91 |         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