Submission #668209

#	Time	Username	Problem	Language	Result	Execution time	Memory
668209		ktkerem	Railway (BOI17_railway)	C++17	100 / 100	256 ms	107340 KiB

railway

/*#pragma GCC target ("avx2")
#pragma GCC optimize ("O3")
#pragma GCC optimize("Ofast")
#pragma GCC optimize ("unroll-loops")
#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,tune=native")/**/
#include<bits/stdc++.h>
/**/
//typedef int ll;
typedef long long ll;
typedef unsigned long long ull;
typedef std::string str;
//typedef vector<std::vector<ll>> vv; 
/*typedef __int128 vll;
typedef unsigned __int128 uvll;*/
#define llll std::pair<ll , ll>
#define pb push_back
#define pf push_front
#define halo cout << "hello\n"
#define fi first
#define sec second
#define vv(x) std::vector<std::vector<x>>
#define all(a) a.begin() , a.end()
const ll limit = 1e9+7; 
const ll ous = 3e5 + 7;
const ll dx[4] = {-1 , 0 , 1 , 0} , dy[4] = {0,1,0,-1};
ll n , m , k;std::vector<ll> ar , par , kt , fs(ous , 0) , tb(ous , 0) , lev(ous , 0) , lg2(ous , 0);
std::vector<ll> dspar(ous , 0) , dssz(ous , 0) , dsval(ous , 0) , gk(ous , 0);
std::vector<llll> adj[ous] , scpar;
std::vector<std::vector<ll>> spar(ous , std::vector<ll>(20 , 0));
ll tmr = 0;
ll fnd(ll x){
    if(x == dspar[x]){
        return x;
    }
    return dspar[x] = fnd(dspar[x]);
}
void mrg(ll x , ll y){
    x = fnd(x);y = fnd(y);
    if(x != y){
        if(dssz[y] > dssz[x]){
            std::swap(x , y);
        }
        dssz[x] += dssz[y];
        dspar[y] = x; 
    }
}
void dfs(ll cur , ll prv){
    tmr++;
    lev[cur] = lev[prv] - 1;
    ll k = tmr;
    tb[k] = cur;
    fs[cur] = ar.size();
    spar[ar.size()][0] = k;
    ar.pb(k);
    for(auto j:adj[cur]){
        if(j.fi != prv){
            par[j.fi] = j.sec;
            dfs(j.fi , cur);
        }
        spar[ar.size()][0] = k;
        ar.pb(k);
    }
}
bool cmp(ll x , ll y){
    return fs[x] < fs[y];
}
void sdfs(ll crt , ll prv){
    for(auto j:adj[crt]){
        if(j.fi != prv){
            sdfs(j.fi , crt);
        }
    }
    gk[par[crt]]+= kt[crt];
    kt[prv]+=kt[crt];
}
void solve(){
    std::cin >> n >> m >> k;
    par.resize(n+5);
    kt.resize(n+5);
    lg2[1] = 0;
    for(ll i = 2;ous > i;i++){
        lg2[i] = lg2[i/2] + 1;
    }
    for(ll i = 1;n>i;i++){
        ll x , y;std::cin >> x >> y;
        adj[x].pb({y , i});
        adj[y].pb({x , i});
    }
    dfs(1 , 0);
    for(ll j = 1;20>j;j++){
        for(ll i = 0;ar.size()>i + (1 << j);i++){
            spar[i][j] = std::min(spar[i][j-1] , spar[i + (1 << j-1)][j-1]);
        }
    }
    //std::cout << spar[0][0] << "\n";
    for(ll i = 0;m>i;i++){
        ll x;std::cin >> x;
        std::vector<ll> o;
        for(ll j = 0;x>j;j++){ll y;std::cin >> y;o.pb(y);kt[y]++;}
        std::sort(all(o) , cmp);
        std::set<std::pair<llll , llll>> st;
        for(ll j = 0;x>j;j++){
            dsval[j] = o[j];
            dspar[j] = j;
            dssz[j] = 1;
        }
        ll alc = o[0];
        for(ll j = 1;x > j;j++){
            ll mn = std::min(fs[o[j-1]] , fs[o[j]]) , mx = std::max(fs[o[j-1]] , fs[o[j]]);
            ll tt = lg2[mx - mn + 1];
            ll lc = std::min(spar[mn][tt] , spar[mx - (1ll << tt) + 1][tt]);
            ll pt = tb[lc];
            mn = std::min(fs[alc] , fs[o[j]]) , mx = std::max(fs[alc] , fs[o[j]]);
            tt = lg2[mx - mn + 1];
            lc = std::min(spar[mn][tt] , spar[mx - (1ll << tt) + 1][tt]);
            alc = tb[lc];
            //std::cout << pt << " " << dsval[j] << " " << dsval[j-1] << "\n"; 
            st.insert({{lev[pt] , pt} , {j , j-1}});
        }
        kt[alc]--;
        while(st.size()){
            std::pair<llll , llll> a = *st.begin();
            st.erase(st.begin());
            ll x = fnd(a.sec.fi) , y = fnd(a.sec.sec);
            if(x != a.sec.fi || y != a.sec.sec){
                ll mn = std::min(fs[dsval[x]] , fs[dsval[y]]) , mx = std::max(fs[dsval[x]] , fs[dsval[y]]);
                ll tt = lg2[mx - mn + 1];
                ll lc = std::min(spar[mn][tt] , spar[mx - (1ll << tt) + 1][tt]);
                ll o = tb[lc];
                st.insert({{lev[o] , o} , {x , y}});
            }
            else{
                mrg(a.sec.fi , a.sec.sec);
                dsval[fnd(a.sec.fi)] = a.fi.sec;
                //std::cout << a.fi.fi << " " << a.fi.sec << " " << dsval[a.sec.fi] << " " << dsval[a.sec.sec] << "\n";
                kt[a.fi.sec]--;
            }
        }
    }
    sdfs(1 , 0);
    std::vector<ll> ans;
    for(ll i = 1;n>i;i++){
        if(gk[i] >= k){
            ans.pb(i);
            //std::cout << i << "\n";
        }
    }
    std::cout << ans.size() << "\n";
    for(auto j:ans){
        std::cout << j << " ";
    }
    std::cout <<"\n";
    return;/**/
}
signed main(){
    std::ios_base::sync_with_stdio(false);std::cin.tie(NULL);
    ll t=1;
    //std::cin >> t;
    ll o = 1;
    while(t--){ 
        //cout << "Case " << o++ << ":\n";
        solve();
    }
    return 0;
}/**/

Compilation message (stderr)

railway.cpp:5:78: warning: "/*" within comment [-Wcomment]
    5 | #pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,tune=native")/**/
      |                                                                               
railway.cpp: In function 'void solve()':
railway.cpp:91:31: warning: comparison of integer expressions of different signedness: 'std::vector<long long int>::size_type' {aka 'long unsigned int'} and 'll' {aka 'long long int'} [-Wsign-compare]
   91 |         for(ll i = 0;ar.size()>i + (1 << j);i++){
      |                      ~~~~~~~~~^~~~~~~~~~~~~
railway.cpp:92:66: warning: suggest parentheses around '-' inside '<<' [-Wparentheses]
   92 |             spar[i][j] = std::min(spar[i][j-1] , spar[i + (1 << j-1)][j-1]);
      |                                                                 ~^~
railway.cpp: In function 'int main()':
railway.cpp:159:8: warning: unused variable 'o' [-Wunused-variable]
  159 |     ll o = 1;
      |        ^

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