Submission #868528

#	Time	Username	Problem	Language	Result	Execution time	Memory
868528		LeVanThuc	Hard route (IZhO17_road)	C++17	0 / 100	5 ms	21492 KiB

road

#include<bits/stdc++.h>
using namespace std;
#define ll long long
#define fi first
#define se second
#define p(x,y) pair<ll,ll>(x,y)
#define BIT(i,x) ((x>>i)&1)
#define MASK(x) (1<<x)
#define ld long double
#define __builtin_popcount __builtin_popcountll
#define pll pair<ll,ll>
template<class T1,class T2>
bool maximize(T1 &x,const T2 &y)
{
    if(x<y)
    {
        x=y;
        return 1;
    }
    return 0;
}
template<class T1,class T2>
bool minimize(T1 &x,const T2 &y)
{
    if(x>y)
    {
        x=y;
        return 1;
    }
    return 0;
}
void online()
{
    std::ios_base::sync_with_stdio(0);
    cin.tie(0);
#ifdef thuc
    freopen("input.INP","r",stdin);
    freopen("output.OUT","w",stdout);
#else

#endif
}
ll root=1;
const ll N=5e5+10,M=1e9+7;
ll par[N],in[N],cnt[N],n,out[N],cnt2[N];
pll in2[N];
vector<ll> gr[N];
void dfs(ll u)
{
    cnt[u]=1;
    in[u]=1;
    for(auto v:gr[u])
    {
        if(v==par[u]) continue;
        par[v]=u;
        dfs(v);
        if(maximize(in[u],in[v]+1)) cnt[u]=0;
        if(in[u]==in[v]+1)
        {
            cnt[u]+=cnt[v];
        }
    }
}
vector<pll> ans;
void dp(ll u)
{
    vector<ll> lst;
    lst.push_back(out[u]);
    for(auto v:gr[u])
    {
        if(v==par[u]) continue;
        lst.push_back(in[v]);
    }
    sort(lst.begin(),lst.end(),greater<ll>());
    vector<pll> vt;
    for(auto v:gr[u])
    {
        if(v==par[u]) continue;
        if(in[v]==lst[0]) out[v]=lst[1]+1;
        else out[v]=lst[0]+1;
        vt.emplace_back(in[v],cnt[v]);
        dp(v);
    }
    sort(vt.begin(),vt.end(),greater<pll>());
    if(vt.size()>1)
    {
        vector<ll> mi;
        vector<ll> ha;
        for(auto v:vt)
        {
            if(v.fi==vt[0].fi) mi.push_back(v.se);
        }
        if(mi.size()<vt.size())
            for(auto v:vt)
            {
                if(v.fi==vt[mi.size()].fi) ha.push_back(v.se);
            }
        ll dis=out[u];
        if(mi.size()>=3)
        {
            maximize(dis,vt[0].fi);
            ll cnt=0;
            ll res=0;
            for(int i=0; i<mi.size(); i++)
            {
                res+=mi[i]*cnt;
                cnt+=mi[i];
            }
            ans.emplace_back(dis*vt[0].fi*2,cnt);
            return;
        }
        if(mi.size()==2)
        {
            if(dis>=vt[0].fi||vt.size()==2)
                ans.emplace_back(dis*vt[0].fi*2,mi[0]*mi[1]);
            else
            {
                ll res=0,ok=mi[0]+mi[1];
                for(int j=0; j<ha.size(); j++)
                {
                    res+=ok*ha[j];
                }
                ans.emplace_back(vt[0].fi*(vt[0].fi+vt[2].fi),res);
            }
            return ;
        }
        if(mi.size()==1)
        {
            if(dis>=mi[0])
            {
                ll res=0;
                for(int j=0; j<ha.size(); j++)
                {
                    res+=mi[0]*ha[j];
                }
                ans.emplace_back(dis*(vt[0].fi+vt[mi.size()].fi),res);
            }
            else
            {
                dis=vt[0].fi;
                mi=ha;
                if(mi.size()>=2)
                {
                    ll cnt=0;
                    ll res=0;
                    for(auto v:mi)
                    {
                        res+=cnt*v;
                        cnt+=v;
                    }
                    ans.emplace_back(dis*vt[1].fi*2,res);
                }
                else
                {
                    ha.clear();
                    if(vt.size()>mi.size()+1)
                    {
                        for(auto v:vt) if(v.fi==vt[mi.size()+1].fi) ha.push_back(v.se);

                    ll res=0;
                    for(auto v:ha)
                    {
                        res+=mi[0]*v;
                    }
                    ans.emplace_back(dis*(vt[1].fi+vt[2].fi),res);
                    }
                    else
                    {
                        ans.emplace_back(0,1);
                    }
                }
            }
            return;
        }
    }
}
int main()
{
    online();
    cin>>n;
    if(n==2)
    {
        cout<<0;
        return 0;
    }
    for(int i=0; i<=n; i++) out[i]=0;
    for(int i=1; i<n; i++)
    {
        ll u,v;
        cin>>u>>v;
        gr[u].push_back(v);
        gr[v].push_back(u);
        if(gr[u].size()>1) root=u;
        if(gr[v].size()>1) root=v;
    }
    dfs(root);
    dp(root);
    sort(ans.begin(),ans.end(),greater<pll>());
    cout<<ans[0].fi<<' ';
    ll cnt=0;
    for(int i=0; i<ans.size(); i++) if(ans[i].fi==ans[0].fi) cnt+=ans[i].se;
    cout<<cnt;
}

Compilation message (stderr)

road.cpp: In function 'void dp(long long int)':
road.cpp:104:27: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  104 |             for(int i=0; i<mi.size(); i++)
      |                          ~^~~~~~~~~~
road.cpp:119:31: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  119 |                 for(int j=0; j<ha.size(); j++)
      |                              ~^~~~~~~~~~
road.cpp:132:31: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  132 |                 for(int j=0; j<ha.size(); j++)
      |                              ~^~~~~~~~~~
road.cpp: In function 'int main()':
road.cpp:201:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<long long int, long long int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  201 |     for(int i=0; i<ans.size(); i++) if(ans[i].fi==ans[0].fi) cnt+=ans[i].se;
      |                  ~^~~~~~~~~~~

• Subtask 1: 0 / 19
• Subtask 2: 0 / 33
• Subtask 3: 0 / 48