Submission #652818

#	Time	Username	Problem	Language	Result	Execution time	Memory
652818		raysh07	Sightseeing (NOI14_sightseeing)	C++14	15 / 25	1569 ms	262144 KiB

sightseeing

#include <bits/stdc++.h>
using namespace std;
#define int long long

mt19937_64 RNG(chrono::steady_clock::now().time_since_epoch().count());
const int maxn = 5e6 + 69;
//vector <pair<int, int>> adj[maxn];
int d[maxn];
int sz[maxn];
int root[maxn];
vector <int> st[maxn];
int ans[maxn];
//set <int> st[maxn];
//const int maxn = 5e5 + 69;

int findroot(int x)
{
    while (x!=root[x])
    x = root[x];
    return x;
}

void unite(int x, int y)
{
    //x = findroot(x);
    //y = findroot(y);
    if (x==y)
    return;
    
    if (sz[x]<sz[y])
    swap(x, y);
    
    sz[x] += sz[y];
    root[y] = x;
    
    for (int i=0; i<st[y].size(); i++)
    st[x].push_back(st[y][i]);
}

void Solve() 
{
    int v, e, q;
    cin>>v>>e>>q;
    vector <pair<int, pair<int, int>>> edg;
    for (int i=0; i<e; i++)
    {
        int a, b, c;
        cin>>a>>b>>c;
        a--;
        b--;
        //adj[a].push_back(make_pair(b,c));
        //adj[b].push_back(make_pair(a, c));
        edg.push_back(make_pair(c, make_pair(a, b)));
    }
    
    sort(edg.begin(), edg.end(), greater<pair<int, pair<int, int>>>());
    
    for (int i=0; i<v; i++)
    {
        sz[i] = 1;
        root[i] = i;
        st[i].push_back(i);
    }
    
    for (int i=0; i<e; i++)
    {
        int u = edg[i].second.first;
        int v = edg[i].second.second;
        //cout<<edg[i].first<<"\n";
        u = findroot(u);
        v = findroot(v);
        if (v==findroot(0))
        {
            swap(u, v);
        }
        if (u==findroot(0) && v!=findroot(0))
        {
            //cout<<"YES "<<i+1<<" "<<v+1<<"\n";
            for (int j=0; j<(int)(st[v].size()); j++)
            {
                //cout<<"UPDATED "<<st[v][j] + 1<<" "<<edg[i].first<<"\n";
                ans[st[v][j]] = edg[i].first;
            }
        }
        
        unite(u, v);
        //cout<<"PRINTING\n";
        //for (int j=0; j<n; j++)
        //{
            
        //}
    }
    for (int i=0; i<q; i++)
    {
        int x;
        cin>>x;
        x--;
        cout<<ans[x]<<"\n";
    }
}

int32_t main() 
{
    //freopen(".in",  "r", stdin);
    //freopen(".out", "w", stdout);
    auto begin = std::chrono::high_resolution_clock::now();
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    int t = 1;
    //cin >> t;
    for(int i = 1; i <= t; i++) 
    {
        //cout << "Case #" << i << ": ";
        Solve();
    }
    auto end = std::chrono::high_resolution_clock::now();
    auto elapsed = std::chrono::duration_cast<std::chrono::nanoseconds>(end - begin);
    cerr << "Time measured: " << elapsed.count() * 1e-9 << " seconds.\n"; 
    return 0;
}

Compilation message (stderr)

sightseeing.cpp: In function 'void unite(long long int, long long int)':
sightseeing.cpp:36:20: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   36 |     for (int i=0; i<st[y].size(); i++)
      |                   ~^~~~~~~~~~~~~

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