Submission #1172399

#	Time	Username	Problem	Language	Result	Execution time	Memory
1172399		DanielPr8	Railway (BOI17_railway)	C++20	0 / 100	32 ms	21168 KiB

railway

#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using vll = vector<ll>;
using vvl = vector<vll>;
using pll = pair<ll,ll>;
using vpl = vector<pll>;
using vvp = vector<vpl>;
#define f first
#define s second
#define pb push_back
#define all(v) v.begin(),v.end()
vll ed, sz;
vpl ord;
vvp g;
void dfs(ll cr, ll pr){
    ord.pb({cr, -1});
    for(pll i:g[cr]){
        if(i.f!=pr){
            ord.back() = {cr, i.s};
            dfs(i.f,cr);
        }
    }
}
int main(){
    ios_base::sync_with_stdio(0);cin.tie(NULL);
    ll n, m, k, a ,b, s;
    cin >> n >> m >> k;
    g = vvp(n);
    for(ll i = 0; i < n-1; ++i){
        cin >> a >> b;
        a--;b--;
        g[a].pb({b,i});
        g[b].pb({a,i});
    }
    ll ms=0;
    for(ll i = 0; i < n; ++i){if(g[i].size()==1)ms=i;}
    dfs(ms, ms);
    vll pl(n);
    ed = vll(n-1);
    for(ll i = 0; i < n; ++i)pl[ord[i].f]=i;
    vll ac(n-1);
    for(ll i = 0; i < m; ++i){
        ll mn = 1e9, mx = 0;
        cin >> s;
        while(s--){
            cin >> a;a--;
            mx = max(mx, pl[a]);
            mn = min(mn, pl[a]);
        }
        ac[mn]++;
        ac[mx]--;
    }
    for(ll i = 0; i < n; ++i){
        if(i>0)ac[i]+=ac[i-1];
        ed[ord[i].s]=ac[i];
    }
    vll ans;
    for(ll i = 0; i < n-1; ++i){
        if(ed[i]>=k)ans.pb(i+1);
    }
    cout << ans.size() << "\n";
    for(ll i:ans)cout << i << " ";
}

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