Submission #1004345

#	Time	Username	Problem	Language	Result	Execution time	Memory
1004345		vjudge1	Railway (BOI17_railway)	C++17	0 / 100	1062 ms	28864 KiB

railway

#pragma GCC optimize("-O3")
#include<bits/stdc++.h>
#include<ext/pb_ds/assoc_container.hpp>
#include<ext/pb_ds/tree_policy.hpp>
#define ll long long
#define ld long double
#define vl vector<ll>
#define vi vector<int>
#define pii pair<int, int>
#define pll pair<ll, ll>
#define all(v) v.begin(), v.end()
#define rall(v) v.rbegin(), v.rend()
#define pb push_back
#define p_b pop_back
#define f first
#define s second
using namespace std;
using namespace __gnu_pbds;
typedef tree<int, null_type, less_equal<int>, rb_tree_tag, tree_order_statistics_node_update> ordered_set;
const ll sz = 1e5+5;
vl g[sz];
set<ll>st[sz], stt[2];
ll vis[sz];
void dfs(ll f, ll node, ll h)
{
    vis[node] = 1;
    for(auto h : st[node])
        stt[f].insert(h);
    for(auto u : g[node])
    {
        if(vis[u] || u == h)
            continue;
        dfs(f, u, h);
    }
}
void solve()
{
    ll n, m, k, i, j;
    cin >> n >> m >> k;
    vector<pll>vect;
    for(i = 1; i <= n - 1; i++)
    {
        ll x, y;
        cin >> x >> y;
        g[x].pb(y);
        g[y].pb(x);
        vect.pb({x, y});
    }
    for(i = 1; i <= m; i++)
    {
        ll s;
        cin >> s;
        for(j = 1; j <= s; j++)
        {
            ll x;
            cin >> x;
            st[x].insert(i);
        }
    }
    vl f;
    for(i = 0; i < vect.size(); i++)
    {
        for(j = 1; j <= n; j++)
            vis[j] = 0;
        stt[0].clear();
        stt[1].clear();
        ll x = vect[i].f, y = vect[i].s;
        dfs(0, x, y);
        dfs(1, y, x);
        set<ll> st1 = stt[0], st2 = stt[1];
        ll sm = 0;
        for(auto u : st2)
        {
            ll sz = st1.size();
            st1.insert(u);
            if(sz == st1.size())
                sm++;
        }
        if(sm >= k)
            f.pb(i+1);
    }
    cout << f.size() << "\n";
    for(auto u : f)
        cout << u << ' ';
    cout << "\n";
}
int main()
{
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);
    ll tests = 1;
    //cin >> tests;
    while(tests--)
    {
        solve();
    }
}

Compilation message (stderr)

railway.cpp: In function 'void solve()':
railway.cpp:61:18: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<std::pair<long long int, long long int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   61 |     for(i = 0; i < vect.size(); i++)
      |                ~~^~~~~~~~~~~~~
railway.cpp:76:19: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::set<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   76 |             if(sz == st1.size())
      |                ~~~^~~~~~~~~~~~~

• Subtask 1: 0 / 8
• Subtask 2: 0 / 15
• Subtask 3: 0 / 7
• Subtask 4: 0 / 29
• Subtask 5: 0 / 16
• Subtask 6: 0 / 25