Submission #1271519

#	Time	Username	Problem	Language	Result	Execution time	Memory
1271519		rayan_bd	Cities (BOI16_cities)	C++20	0 / 100	103 ms	21200 KiB

cities

#include <bits/stdc++.h>
using namespace std;
const int mxN = 1e5 + 100;
#define int long long
vector<pair<int, int>> adj[mxN];
int par[mxN], mark[mxN], sum[mxN], bad = 0;
int find(int u){
    if(u == par[u]) return u;
    return par[u] = find(par[u]);
}
int unite(int u, int v){
    u = find(u), v = find(v);
    if(u ^ v) return par[u] = v;
    return 0;
}
void dfs(int u, int par){
    for(auto it : adj[u]){
        if(it.first ^ par){
            dfs(it.first, u);
            mark[u] |= mark[it.first];
            sum[u] += sum[it.first] + it.second;
        }
    }
    if(mark[u] == 0){
        bad += sum[u];
        sum[u] = 0;
    }
}
signed main(){
    ios_base::sync_with_stdio(0);
    cin.tie(nullptr); cout.tie(nullptr);
    int n, m, e, u, v, w, marked = 0, cost = 0;
    cin >> n >> m >> e;
    for(int i = 1; i <= m; ++i){
        cin >> u;
        marked = u;
        mark[u] = 1;
    }
    for(int i = 1; i <= n; ++i) par[i] = i;
    vector<vector<int>> edge;
    for(int i = 1; i <= e; ++i){
        cin >> u >> v >> w;
        edge.push_back({w, u, v});
    }
    sort(edge.begin(), edge.end());
    for(auto it : edge){
        if(unite(it[1], it[2])){
            cost += it[0];
            adj[it[1]].push_back({it[2], it[0]});
            adj[it[2]].push_back({it[1], it[0]});
        }
    }
    dfs(marked, -1);
    cout << cost - bad << "\n";
    return 0;
}

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