Submission #1133644

#	Time	Username	Problem	Language	Result	Execution time	Memory
1133644		thelegendary08	Railway (BOI17_railway)	C++17	23 / 100	254 ms	42592 KiB

railway

#include<bits/stdc++.h>
#define pb push_back
#define mp make_pair
#define int long long
#define vi vector<int>
#define vvi vector<vector<int>>
#define pii pair<int, int>
#define vpii vector<pair<int, int>>
#define vc vector<char>
#define vb vector<bool>
#define mii map<int,int>
#define f0r(i,n) for(int i=0;i<n;i++)
#define FOR(i,k,n) for(int i=k;i<n;i++)
#define all(v) (v).begin(),(v).end()
#define rall(v) (v).rbegin(),(v).rend()
#define in(a) int a; cin>>a
#define in2(a,b) int a,b; cin>>a>>b
#define in3(a,b,c) int a,b,c; cin>>a>>b>>c
#define in4(a,b,c,d) int a,b,c,d; cin>>a>>b>>c>>d
#define vin(v,n); vi v(n); f0r(i,n){cin>>v[i];}
#define out(a) cout<<a<<'\n'
#define out2(a,b) cout<<a<<' '<<b<<'\n'
#define out3(a,b,c) cout<<a<<' '<<b<<' '<<c<<'\n'
#define out4(a,b,c,d) cout<<a<<' '<<b<<' '<<c<<' '<<d<<'\n'
#define pout(a) cout<<a.first<<' '<<a.second<<'\n'
#define vout(v) for(auto u : v){cout<<u<<' ';} cout<<'\n'
#define dout(a) cout<<a<<' '<<#a<<'\n'
#define dout2(a,b) cout<<a<<' '<<#a<<' '<<b<<' '<<#b<<'\n'
#define yn(x); if(x){cout<<"YES"<<'\n';}else{cout<<"NO"<<'\n';}
const int leg = 1e9 + 7;
const int mod = 998244353;
using namespace std;
const int mxn = 1e5 + 5;
vi adj[mxn]; 
vi start(mxn);
vi par(mxn, -1);
vi et;
int n,m,k;
int timer = 0;
vi dep(mxn);
void dfs(int cur, int from){
	par[cur] = from;
	et.pb(cur);
	start[cur] = timer;
	if(from != -1)dep[cur] = dep[from] + 1;
	timer++;
	for(auto u : adj[cur]){
		if(u != from){
			dfs(u, cur);
		}
		timer++;
		et.pb(cur);
	}
	

}
vpii tree(mxn * 10, {4e18, 0});
void update(int k, int x, int d){
	k += et.size();
	tree[k] = mp(d, x);
	for(k /=2; k >= 1; k/=2){
		tree[k] = min(tree[k*2], tree[k*2+1]);
	}
}
int quer(int l, int r){
	l += et.size();
	r += et.size();
	pii ret = {4e18, 0};
	while(l <= r){
		if(l % 2 == 1)ret = min(ret, tree[l++]);
		if(r % 2 == 0)ret = min(ret, tree[r--]);
		l/=2; r/=2;
	}
	return ret.second;
}
int lca(int a, int b){
	if(start[a] > start[b])swap(a,b);
	return quer(start[a], start[b]);
}
vi path(int a, int b){
	if(a == b)return {a};
	vi c;
	vi d;
	c.pb(a);
	int l = lca(a,b);
	while(a != l){
		a = par[a];
		c.pb(a);
	}
	d.pb(b);
	while(b != l){
		b = par[b];
		d.pb(b);
	}
	if(d.size() != 0)d.pop_back();
	reverse(all(d));
	for(auto u : d)c.pb(u);
	return c;
}
signed main(){
	ios::sync_with_stdio(false);
	cin.tie(NULL);
	//ifstream cin(".in");
	//ofstream cout(".out");
	cin>>n>>m>>k;
	map<pii, int>edge;
	vi deg(n);
	f0r(i,n-1){
		in2(a,b);
		a--;
		b--;
		deg[a]++;
		deg[b]++;
		adj[a].pb(b);
		adj[b].pb(a);
		edge[mp(a,b)] = i;
		edge[mp(b,a)] = i;
	}
	//n<=10000 && m <= 2000
	if(n<=10000 && m <= 2000){
		dfs(0, -1);
		f0r(i, et.size()){
			update(i, et[i], dep[et[i]]);
		}
		//vout(et);
		//f0r(i,n)cout<<par[i]<<' ';
		//cout<<'\n';
		f0r(i, n){
			//cout<<start[i]<<' ';
		}
		//cout<<'\n';
		//vout(path(4,2));
		//out(lca(0,2));
		//vout(path(0, 2));
		//vout(path(4,4));
		vi tot(n-1);
		f0r(i,m){
			in(s);
			vi v(s);
			f0r(j, s)cin>>v[j];
			f0r(j,s)v[j]--;
			vi cnt(n-1);
			//vout(v);
			//dout(lca(1,4));
			//vout(path(1,4));
			
			f0r(j, s-1){
				vi cur = path(v[j], v[j+1]);
				
				f0r(K, cur.size() - 1){
					cnt[edge[mp(cur[K], cur[K+1])]] = 1;
				}
				
			}
			
			f0r(j, n-1)tot[j] += cnt[j];
		}
		
		vi ans;
		f0r(i, n-1){
			if(tot[i] >= k)ans.pb(i + 1);
		}
		sort(all(ans));
		out(ans.size());
		vout(ans);
	}
	else{
		//vout(deg);
		int ep = 0;
		f0r(i,n){
			if(deg[i] == 1)ep = i;
		}
		vb vis(n);
		vi path;
		path.pb(ep);
		vis[ep] = 1;
		int cur = ep;
		//cout<<cur<<endl;
		vi edgedex;
		while(true){
			for(auto u : adj[cur]){
				if(vis[u])continue;
				edgedex.pb(edge[mp(u, cur)]);
				vis[u] = 1;
				cur = u;
				path.pb(cur);
			}
			if(deg[cur] == 1)break;
			
			//cout<<cur<<endl;
		}
		//vout(edgedex);
		//vout(path);
		
		vi pathdex(n);
		f0r(i,n){
			pathdex[path[i]] = i;
		}
		
		vi cnt(n-1);
		vi dif(n-1);
		f0r(tt, m){
			in(s);
			vin(v,s);
			//vout(v);
			f0r(i,s)v[i]--;
			//vout(v);
			
			int mn = 4e18;
			int mx = -1;
			f0r(i,s){
				mn = min(mn, pathdex[v[i]]);
				mx = max(mx, pathdex[v[i]]);
			}
			mx--;
			//out2(mn, mx);
			
			dif[mn]++;
			if(mx != n-1)dif[mx+1]--;
			
		}
		
		cnt[0] = dif[0];
		FOR(i, 1, n-1){
			cnt[i] = dif[i] + cnt[i-1];
		}
		//vout(cnt);
		vi ans;
		f0r(i, n-1){
			if(cnt[i] >= k){
				ans.pb(edgedex[i]+1);
			}
		}
		out(ans.size());
		vout(ans);	
	}
}

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