oj.uz

Submission #442747

# Submission time Handle Problem Language Result Execution time Memory
442747 2021-07-08T20:11:16 Z leaked Shymbulak (IZhO14_shymbulak) C++14
100 / 100
 208 ms 27156 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)%sz(cyc)];
            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 4940 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 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
20.0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 4 ms 5068 KB Output is correct
2 Correct 3 ms 5020 KB Output is correct
3 Correct 4 ms 5068 KB Output is correct
4 Correct 4 ms 5068 KB Output is correct
5 Correct 5 ms 5324 KB Output is correct
6 Correct 7 ms 5572 KB Output is correct
7 Correct 6 ms 5452 KB Output is correct
8 Correct 5 ms 5432 KB Output is correct
9 Correct 5 ms 5324 KB Output is correct
10 Correct 5 ms 5324 KB Output is correct

Subtask #3
50.0 / 50.0

# Verdict Execution time Memory Grader output
1 Correct 73 ms 12064 KB Output is correct
2 Correct 69 ms 12168 KB Output is correct
3 Correct 77 ms 19088 KB Output is correct
4 Correct 50 ms 11844 KB Output is correct
5 Correct 52 ms 11860 KB Output is correct
6 Correct 208 ms 18500 KB Output is correct
7 Correct 111 ms 15164 KB Output is correct
8 Correct 102 ms 18544 KB Output is correct
9 Correct 104 ms 18704 KB Output is correct
10 Correct 97 ms 19724 KB Output is correct
11 Correct 103 ms 26036 KB Output is correct
12 Correct 109 ms 27156 KB Output is correct