Submission #808551

#	Time	Username	Problem	Language	Result	Execution time	Memory
808551		shadow_sami	Railway (BOI17_railway)	C++17	100 / 100	108 ms	46868 KiB

railway

#include<bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace __gnu_pbds;
using namespace std;
typedef long long int ll;
typedef vector<ll> vi;
typedef vector<vector<ll>> vvi;
typedef pair<ll,ll> pi;
typedef map<ll,ll> mi;
typedef long double ld;
typedef vector<ld> vd;
typedef vector<vector<ld>> vvd;
typedef pair<ld,ld> pd;
#define ff first
#define ss second
#define srt(a) sort(a.begin(),a.end());
#define fip(k, n) for (ll i = k; i < n; i++)
#define fjp(k, n) for (ll j = k; j < n; j++)
#define fin(k, n) for (ll i = k; i >= n; i--)
#define fjn(k, n) for (ll j = k; j >= n; j--)
#define fp(k, n, m) for (ll k = n; k < m; k++)
#define fn(k, n, m) for (ll k = n; k >= m; k--)
#define ordered_set tree<pi, null_type,less< pi >, rb_tree_tag,tree_order_statistics_node_update>
#define totalOne(n) __builtin_popcount(n)
#define backZero(n) __builtin_ctzll(n)
#define frontZero(n) __builtin_clzll(n)
#define fx(k) for ( auto x : k )
#define test ll t;cin >> t;while (t--)
#define nli "\n"

// ==========================(debug)============================================================================================== //

#ifndef ONLINE_JUDGE
#define debug(x) cerr << #x <<" "; _printn(x); cerr << nli;
#else
#define debug(x)
#endif

void _printn(ll x){ cerr<<x<<" "; }
void _printn(int x){ cerr<<x<<" "; }
void _printn(ld x){ cerr<<x<<" "; }
void _printn(double x){ cerr<<x<<" "; }
void _printn(string x){ cerr<<x<<" "; }
void _printn(char x){ cerr<<x<<" "; }
void _printn(bool x){ cerr<<x<<" "; }
template<class T,class V>void _printn(pair<T,V> vv);
template<class T> void _printn(vector<T> vv);
template<class T> void _printn(set<T> vv);
template<class T,class V> void _printn(map<T,V> vv);
template<class T> void _printn(multiset<T> vv);
template<class T,class V>void _printn(pair<T,V> vv){ cerr<<"( ";_printn(vv.ff);cerr<<",";_printn(vv.ss);cerr<<")";}
template<class T> void _printn(vector<T> vv){ cerr<<"[ "; for(auto xx:vv){ _printn(xx);cerr<<" "; } cerr<<"]"; };
template<class T> void _printn(set<T> vv){ cerr<<"{ "; for(auto xx:vv){ _printn(xx);cerr<<" "; } cerr<<"}"; };
template<class T> void _printn(multiset<T> vv){ cerr<<"{ "; for(auto xx:vv){ _printn(xx);cerr<<" "; } cerr<<"}"; };
template<class T,class V> void _printn(map<T,V> vv){ cerr<<"{ "; for(auto xx:vv){ _printn(xx);cerr<<" "; } cerr<<"}"; };

// ==========================(debug)============================================================================================== //

ll n,m,tp,tp2,res,cnt,sum,tptp,ans;
const ll mx = 5e5+5;
const ll mod = 1e9+7;

// ==========================(MOD)=============================================================================================== //

ll mod_add(ll aa,ll bb){ return ((aa%mod)+(bb%mod))%mod; }
ll mod_minus(ll aa,ll bb){ return (((aa%mod)-(bb%mod))+10*mod)%mod; }
ll mod_mul(ll aa,ll bb){ return ((aa%mod)*(bb%mod))%mod; }
ll mod_power(ll aa,ll bb){ aa%=mod; ll empowered = 1; bb%=mod-1; while(bb > 0){ if(bb & 1) empowered = mod_mul(empowered,aa); bb = bb >> 1; aa = mod_mul(aa,aa); } return empowered; }
ll mod_divi(ll aa,ll bb){ aa=mod_mul(aa,mod_power(bb,mod-2)); return aa; }

// ==========================(MOD)=============================================================================================== //

bool f = false;
ll k;
vi na;
vector<pi> adj[mx];
ll st[mx];
ll en[mx];
ll dep[mx];
ll up[mx][20];
int sr,de;
ll timer = 0;
ll val[mx];
ll dp[mx];

void dfs(ll u,ll par){
	up[u][0] = par;
	st[u] = timer;
	timer++;
	fjp(1,20)
		up[u][j] = up[up[u][j-1]][j-1];
	fx(adj[u])
		if(x.ff!=par){
			dep[x.ff] = dep[u] + 1;
			dfs(x.ff,u);
		}
	en[u] = timer - 1;
	return;
}

ll lca(ll aa,ll bb){
	if(dep[aa] < dep[bb])
		swap(aa,bb);
	tptp = dep[aa] - dep[bb];
	fjp(0,20)
		if(tptp & (1<<j))
			aa = up[aa][j];
	if(aa==bb)
		return aa;
	fjn(19,0)
		if(up[aa][j] != up[bb][j]){
			aa = up[aa][j];
			bb = up[bb][j];
		}
	return up[aa][0];
}

void dfs2(ll u,ll par){
	fx(adj[u])	
	if(x.ff!=par){
		dfs2(x.ff,u);
		dp[u]+=dp[x.ff];
		if(dp[x.ff]>=2*k)
			na.push_back(x.ss);
	}
	return;
}

void upd(ll aa,ll bb){
	res = lca(aa,bb);
	dp[aa]++;
	dp[bb]++;
	dp[res]-=2;
	return;
}

int main(){
    ios_base::sync_with_stdio(false);cin.tie(0);cout.tie(0);
    // #ifndef ONLINE_JUDGE
    //     freopen("input1.txt", "r", stdin);
    //     freopen("output1.txt", "w", stdout);
    //     freopen("error1.txt", "w", stderr);
    // #endif // ONLINE_JUDGE

        cin>>n>>m>>k;
        fip(0,n-1){
        	cin>>sr>>de;
        	adj[sr].push_back({de,i});
        	adj[de].push_back({sr,i});
        }
        dep[1] = 0;
        dfs(1,1);
        vi a;
        fip(0,m){
        	a.clear();
        	cin>>tp;
        	fjp(0,tp){
        		cin>>res;
        		a.push_back(res);
        	}
        	sort(a.begin(),a.end(),[](const ll &aa,const ll &bb){
        		return st[aa] < st[bb];
        	});
        	fip(0,tp)
        		upd(a[i],a[(i+1)%tp]);
        }
        dfs2(1,1);
        srt(na);
        cout<<(int)na.size()<<nli;
        fx(na)
        	cout<<x+1<<" ";
        
    // cerr << "Time elapsed: " << setprecision(6) << 1000.0 * clock() / CLOCKS_PER_SEC << "ms\n";
    return 0;
}

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