oj.uz

답안 #442746

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
442746 2021-07-08T20:05:59 Z leaked 관광지 (IZhO14_shymbulak) C++14
80 / 100
 173 ms 27064 KB 
#include <bits/stdc++.h>
//#pragma GCC optimize("unroll-loops")
//#pragma GCC optimize("Ofast")
//#pragma GCC optimize("-O3")
//#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,tune=native")
#define vec vector
#define sz(x) ( int)x.size()
#define m_p make_pair
#define f first
#define s second
#define pb push_back
#define all(x) x.begin(),x.end()
#define rall(x) x.rbegin(),x.rend()
#define int long long
using namespace std;
typedef long long ll;
typedef pair<ll, int> pli;
typedef pair<int,ll> pil;
typedef pair<int,int> pii;
typedef unsigned long long ull;
auto rng=bind(uniform_int_distribution<int>(1,1000),mt19937(time(0)));
template<class T> bool umax(T &a,const T &b){return (a<b?a=b,1:0);}
template<class T> bool umin(T &a,const T &b){return (a>b?a=b,1:0);}
const int N=2e5+1;
vec<int> g[N];
int n;
int dst[N];
int used[N],pr[N];
vec<int>cyc;
//vec<int>g
void dfs(int v,int p){
    used[v]=1;
    for(auto &z : g[v]){
        if(z==p) continue;
        if(used[z]==1 && !sz(cyc)){
            int u=v;
            while(u!=z){
                cyc.pb(u);
                u=pr[u];
            }
            cyc.pb(u);
        }
        else if(!used[z]){
             pr[z]=v;
             dfs(z,v);
        }
    }
    used[v]=2;
}
pii ans=m_p(0,0);
pii dp[N];
void upd(pii &a,pii b){
    if(a.f<b.f) a=b;
    else if(a.f==b.f) a.s+=b.s;
}
void dfs2(int v,int p){
    vec<int>vc;
    dp[v]={0,1};
    for(auto &z : g[v]){
        if(used[z] || z==p) continue;
        dfs2(z,v);
        upd(dp[v],{dp[z].f+1,dp[z].s});
        vc.pb(z);
    }
    int m=sz(vc);
    vec<pii>pref(m),suf(m);
    pii me={0,0};
    for(int i=0;i<m;i++){
        int z=vc[i];
        pref[i]=me;
        upd(me,{dp[z].f+1,dp[z].s});
    }
    for(int i=0;i<m;i++){
        pii x=pref[i];
        if(x.f==0) x.s=1;
        upd(ans,m_p(dp[vc[i]].f+1+x.f,1ll*x.s*dp[vc[i]].s));
    }
}
struct myset{
    map<int,int>mp;
    int ad=0;
    void add(pii x){
        x.f-=ad;
        mp[x.f]+=x.s;
    }
    void del(pii x){
        x.f-=ad;
        assert(mp[x.f]>=x.s);
        mp[x.f]-=x.s;
        if(!mp[x.f]) mp.erase(x.f);
    }
    pii get(){
        pii x={-1e9,-1};
        if(sz(mp)){
            x=*mp.rbegin();
        }
        x.f+=ad;
        return x;
    }
}f,s;
signed main(){
    ios_base::sync_with_stdio(false);cin.tie(0);cout.tie(0);
    cin>>n;
//    assert(n<=500);
    for(int i=0;i<n;i++){
        int v,u;
        cin>>v>>u;--v;--u;
        g[v].pb(u);g[u].pb(v);
    }
    dfs(0,0);
    fill(used,used+n,0);
    for(auto &z : cyc) used[z]=1;
    for(auto &z : cyc){
        dfs2(z,z);
    }
    assert(sz(cyc));
//    cerr<<ans.f<<' '<<ans.s<<endl;
    int l=sz(cyc)/2;
//    cout<<l<<endl;
    for(int i=0;i<sz(cyc);i++){
        int v=cyc[i];
        if(i>l){
            s.add({dp[v].f+sz(cyc)-i,dp[v].s});
        }
        else{
            f.add({dp[v].f+i,dp[v].s});
        }
    }
    auto dst=[&](int i,int j){
        int x=abs(i-j);
        return min(x,sz(cyc)-x);
    };
    for(int i=0;i<sz(cyc);i++){
        int v=cyc[i];
        f.del(dp[v]);
//        cerr<<<<' '<<dp[i].f<<' '<<f.get().f<<' '<<s.get().f<<endl;
        pii me=f.get();
        upd(ans,{me.f+dp[v].f,1ll*me.s*dp[v].s});
        if(sz(cyc)%2==0){
            int u=cyc[(i+l)%2];
            pii x={dp[u].f+dp[v].f,1ll*dp[u].s*dp[u].s};
            upd(ans,x);
        }
        int j=(i+l+1)%sz(cyc);
        int u=cyc[j];
        s.del({dp[u].f+dst(i,j),dp[u].s});
        s.add(dp[v]);
        s.ad++;
        f.ad--;
        f.add({dp[u].f+dst((i+1)%sz(cyc),j),dp[u].s});
    }
    assert(ans.s>=1);
//    cout<<ans.f<<' '<<ans.s<<endl;
    cout<<ans.s;
    return 0;
}

/*
5
1 2
2 3
3 4
4 5
5 1
*/

Subtask #1
30.0 / 30.0

# 결과 실행 시간 메모리 Grader output
1 Correct 3 ms 4940 KB Output is correct
2 Correct 3 ms 4928 KB Output is correct
3 Correct 3 ms 4940 KB Output is correct
4 Correct 3 ms 4940 KB Output is correct
5 Correct 3 ms 5016 KB Output is correct
6 Correct 3 ms 4940 KB Output is correct
7 Correct 3 ms 4940 KB Output is correct
8 Correct 3 ms 4940 KB Output is correct
9 Correct 3 ms 4940 KB Output is correct
10 Correct 3 ms 4940 KB Output is correct
11 Correct 3 ms 4940 KB Output is correct
12 Correct 3 ms 4940 KB Output is correct
13 Correct 3 ms 4940 KB Output is correct
14 Correct 3 ms 5068 KB Output is correct
15 Correct 3 ms 5068 KB Output is correct

Subtask #2
0 / 20.0

# 결과 실행 시간 메모리 Grader output
1 Correct 4 ms 5196 KB Output is correct
2 Correct 3 ms 5068 KB Output is correct
3 Correct 4 ms 5068 KB Output is correct
4 Incorrect 4 ms 5068 KB Output isn't correct
5 Halted 0 ms 0 KB -

Subtask #3
50.0 / 50.0

# 결과 실행 시간 메모리 Grader output
1 Correct 85 ms 11972 KB Output is correct
2 Correct 81 ms 12116 KB Output is correct
3 Correct 76 ms 18984 KB Output is correct
4 Correct 52 ms 11788 KB Output is correct
5 Correct 55 ms 11904 KB Output is correct
6 Correct 173 ms 18496 KB Output is correct
7 Correct 105 ms 14964 KB Output is correct
8 Correct 103 ms 18588 KB Output is correct
9 Correct 105 ms 18672 KB Output is correct
10 Correct 95 ms 19780 KB Output is correct
11 Correct 100 ms 25928 KB Output is correct
12 Correct 114 ms 27064 KB Output is correct