Submission #814748

#	Time	Username	Problem	Language	Result	Execution time	Memory
814748		anton	Sightseeing (NOI14_sightseeing)	C++17	15 / 25	922 ms	262144 KiB

sightseeing

#include<bits/stdc++.h>

using namespace std;
#define int long long
#define pii pair<int, int>

struct Edge{
    int a, b;
    int c;

    Edge(){};
    bool operator<(const Edge& b)const{
        return c<b.c;
    }
    Edge(int _a, int _b, int _c){
        a = _a;
        b= _b;
        c= _c;
    }
};

const int MAX_V = 5*1e5;
const int MAX_E = 5*1e6;
int v, e, q;
vector<pii> adj[MAX_V];
Edge edges[MAX_E];
int dsu[MAX_V], sz[MAX_V];
int cost[MAX_V];

int get_C(int id){
    if(dsu[id]==-1){
        return id;
    }
    else{
        int anc= get_C(dsu[id]);
        dsu[id] = anc;
        return anc;
    }
}

void merge(int a, int b){
    a = get_C(a);
    b = get_C(b);
    if(sz[a]<sz[b]){
        swap(a, b);
    }

    dsu[b] = a;
    sz[a] += sz[b];
}


void dfs(int u, int c, int anc){
    cost[u] = c;
    for(auto v: adj[u]){
        if(v.first!=anc){
            dfs(v.first, min(c, v.second), u);
        }
    }   
}

signed main(){
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    cin>>v>>e>>q;

    for(int i = 0; i<e; i++){
        int a, b;
        int c;
        cin>>a>>b;
        a--;b--;
        cin>>c;
        edges[i] = Edge(a, b, c);
    }

    sort(edges, edges+e);

    fill(dsu, dsu+e, -1);
    fill(sz, sz+e, 1);

    for(int i = e-1; i>=0; i--){
        int a= edges[i].a;
        int b= edges[i].b;
        
        if(get_C(a)!=get_C(b)){
            adj[a].push_back(pii(b, edges[i].c));
            adj[b].push_back(pii(a, edges[i].c));
            merge(a, b);
        }
    }

    dfs(0, 1e18, -1);

    for(int i = 0; i<q; i++){
        int u;
        cin>>u;
        cout<<cost[u-1]<<endl;
    }
}

• Subtask 1: 4 / 4
• Subtask 2: 5 / 5
• Subtask 3: 6 / 6
• Subtask 4: 0 / 10