Submission #1004261

#	Time	Username	Problem	Language	Result	Execution time	Memory
1004261		ayankarimova	Railway (BOI17_railway)	C++14	0 / 100	1054 ms	29908 KiB

railway

#include <bits/stdc++.h>
using namespace std;
#define endl '\n'
#define ll long long
const ll sz=1e5+5;
ll p[sz], used[sz];
vector<ll>g[sz];
    set<ll>s;
    map<ll, ll>mp;
    map<pair<ll, ll>, ll>m1;
/*
{} []
*/
void in(ll x, ll y)
{
    while(y!=x){
        ll a=y, b=p[y];
        //cout<<a<<' '<<b<<endl;
        ll c=a, d=b;
        if(c>d) swap(c, d);
        if(m1[{c, d}]){
           mp[m1[{c, d}]]++;
        }
        y=b;
    }
}
void dfs(ll u)
{
    used[u]=1;
    //cout<<u<<' ';
    for(auto v:g[u]){
        if(!used[v]){
            p[v]=u;
            dfs(v);
        }
    }
}
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;
    }
    for(int i=1; i<=m; i++){
        ll x;
        cin>>x;
        ll k[x+1];
        for(int j=1; j<=x; j++){
            cin>>k[j];
        }
        for(int j=2; j<=x; j++){
            dfs(k[j-1]);
            in(k[j-1], k[j]);
            for(int t=0; t<=n; t++){
                    p[t]=0;
                    used[t]=0;
            }
        }
    }
    for(auto i:mp){
        if(i.second>=k){
            s.insert(i.first);
        }
    }
    cout<<s.size()<<endl;
    for(auto i:s) 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