Submission #1004354

#	Time	Username	Problem	Language	Result	Execution time	Memory
1004354		ayankarimova	Railway (BOI17_railway)	C++14	7 / 100	163 ms	39364 KiB

railway

#include <bits/stdc++.h>
using namespace std;
#define endl '\n'
#define ll long long
const ll sz=1e5+5;
ll p[sz], tt, pos[sz], in[sz], root;
vector<ll>g[sz], vec={0};
    set<ll>s;
    map<ll, ll>mp;
    map<pair<ll, ll>, ll>m1;
/*
{} []
*/
void dfs(ll u, ll par)
{
    vec.push_back(u);
    pos[u]=++tt;
    for(auto v:g[u]){
        if(v!=par){
            dfs(v, u);
        }
    }
}
int main()
{
    ios_base::sync_with_stdio(false);cin.tie(0);cout.tie(0);
    ll n, m, k;
    cin>>n>>m>>k;
    for(int i=1; i<n; i++){
        ll a, b;
        cin>>a>>b;
        g[a].push_back(b);
        g[b].push_back(a);
        m1[{a, b}]=i;
        m1[{b, a}]=i;
        in[a]++; in[b]++;
    }
    for(int i=1; i<=n; i++)
        if(in[i]==1) root=i;

    dfs(root, 0);
    for(int i=1; i<=m; i++){
        ll num;
        cin>>num;
        ll k[num+1];
        for(int j=1; j<=num; j++){
            cin>>k[j];
        }
        for(int j=2; j<=num; j++){
            ll x=k[j-1], y=k[j];
            ll a=pos[x], b=pos[y];
            if(a>b) swap(a, b);
            p[a]++; p[b]--;
        }
    }
    for(int i=1; i<n; i++){
        p[i]+=p[i-1];
        mp[m1[{vec[i], vec[i+1]}]]+=p[i];
        //cout<<p[i]<<' ';
    }
    for(auto i:mp){
        if(i.second>=k){
            s.insert(i.first);
        }
    }
    cout<<s.size()<<endl;
    for(auto i:s) cout<<i<<' ';
}
/*
{} []
4 3 3
2 1
1 4
4 3
3 1 2 3
2 1 4
2 2 3
*/

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