oj.uz

Submission #442745

# Submission time Handle Problem Language Result Execution time Memory
442745 2021-07-08T20:04:53 Z leaked Shymbulak (IZhO14_shymbulak) C++14
80 / 100
 168 ms 27056 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){
            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

# Verdict Execution time Memory Grader output
1 Correct 3 ms 4940 KB Output is correct
2 Correct 3 ms 4940 KB Output is correct
3 Correct 4 ms 5068 KB Output is correct
4 Correct 3 ms 4940 KB Output is correct
5 Correct 3 ms 4940 KB Output is correct
6 Correct 3 ms 4940 KB Output is correct
7 Correct 4 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

# Verdict Execution time Memory 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

# Verdict Execution time Memory Grader output
1 Correct 84 ms 12072 KB Output is correct
2 Correct 87 ms 12080 KB Output is correct
3 Correct 79 ms 19084 KB Output is correct
4 Correct 49 ms 11844 KB Output is correct
5 Correct 57 ms 11876 KB Output is correct
6 Correct 168 ms 18380 KB Output is correct
7 Correct 108 ms 15032 KB Output is correct
8 Correct 105 ms 18632 KB Output is correct
9 Correct 104 ms 18708 KB Output is correct
10 Correct 101 ms 19864 KB Output is correct
11 Correct 112 ms 25908 KB Output is correct
12 Correct 117 ms 27056 KB Output is correct