Submission #341572

#	Time	Username	Problem	Language	Result	Execution time	Memory
341572		beksultan04	Shymbulak (IZhO14_shymbulak)	C++14	100 / 100	507 ms	123016 KiB

shymbulak

#include <bits/stdc++.h>
using namespace std;
#define int long long
#define pii pair<int,int>
#define OK puts("OK");
#define NO puts("NO");
#define YES puts("YES");
#define fr first
#define sc second
#define ret return
#define scanl(a) scanf("%lld",&a);
#define scanll(a,b) scanf("%lld %lld",&a, &b);
#define scanlll(a,b,c) scanf("%lld %lld %lld",&a,&b,&c);
#define scan1(a) scanf("%d",&a);
#define scan2(a,b) scanf("%d %d",&a, &b);
#define scan3(a,b,c) scanf("%d %d %d",&a,&b,&c);
#define all(s) s.begin(),s.end()
#define allr(s) s.rbegin(),s.rend()
#define pb push_back
#define sz(v) (int)v.size()
#define endi puts("");
#define eps 1e-12
const int N = 2e6+12,INF=1e9+7;
vector <pii> gg[N];
vector <int> g[N],cycle,v;
pii ver[N];
bool bosh[N],vis[N];
void dfs_cycle(int x,int p){
    vis[x] = 1;
    int i,j;
    v.pb(x);
    for (i=0;i<g[x].size();++i){
        int to = g[x][i];
        if (vis[to] == 1 && to != p){
            bool f=0;
            for (j=0;j<v.size();++j){
                if (v[j] == to)f=1;
                if (f){
                    cycle.pb(v[j]);
                }

            }
        }
        if (vis[to] == 0){
            dfs_cycle(to,x);
        }
    }
    v.pop_back();
}


int dlina[N],colichestvo[N];
pii ans;
void dfs_diametr(int x,int p){
    int i;
    vector <pii> tmp;
    for (i=0;i<g[x].size();++i){
        if (g[x][i] == p || bosh[g[x][i]])continue;
        dfs_diametr(g[x][i],x);
        tmp.pb({dlina[g[x][i]],colichestvo[g[x][i]]});
    }
    if (tmp.size() == 0){
        colichestvo[x] = 1;
        ret;
    }
    sort(allr(tmp));
    int mx = tmp[0].fr,cnt = tmp[0].sc;
    for (i=1;i<tmp.size();++i){
        if (tmp[i].fr == mx){
            cnt += tmp[i].sc;
        }

    }
    dlina[x] = mx+1;
    colichestvo[x] = cnt;
}

void calc(int x,int y,int m){
    int dist = min(abs(x-y),m-abs(x-y));
    dist += dlina[cycle[x]];
    dist += dlina[cycle[y]];
    if (ans.fr < dist){
        ans.fr = dist;
        ans.sc=0;
    }
    if (dist == ans.fr){
        if (abs(x-y) == (m-abs(x-y))){
            ans.fr += max(colichestvo[cycle[x]],1ll)*max(1ll,colichestvo[cycle[y]])*2ll;
        }
        else
            ans.fr += colichestvo[cycle[x]]*colichestvo[cycle[y]]*1ll;
    }
}

void posledniy_dfs(int x,int p){
    vector <pii> tmp;
    int i;
    for (i=0;i<g[x].size();++i){
        if (g[x][i] == p || bosh[g[x][i]])continue;
        posledniy_dfs(g[x][i],x);
        tmp.pb({dlina[g[x][i]],colichestvo[g[x][i]]});
    }
    if (tmp.size() <2)ret;
    sort(allr(tmp));
    if (tmp.empty())ret;
    vector <int> xixi;
    int mx = tmp[0].fr+1,cnt=tmp[0].sc,f=0;
    if (mx == tmp[1].fr+1){
        xixi.pb(cnt);
        int sum=0,bla=0;
        for (i=1;i<tmp.size();++i){
            if (tmp[i].fr+1+mx > ans.fr){
                ans.fr = tmp[i].fr+1+mx;
                f=2;
            }
            if (ans.fr == tmp[i].fr+1+mx){
                xixi.pb(tmp[i].sc);
                f = max(f,1ll);
            }
            else break;
        }
        for (i=0;i<xixi.size();++i){
            sum+=xixi[i];
            bla += xixi[i]*xixi[i];
        }
        sum *= sum;
        sum-=bla;
        sum/=2;
        if (f==2)ans.sc=sum;
        else if (f==1){
            ans.sc+=sum;
        }
    }
    else {
        int sum=0,bla=0;

        for (i=1;i<tmp.size();++i){
            if (tmp[i].fr+1+mx > ans.fr){
                ans.fr = tmp[i].fr+1+mx;
                f=2;
            }
            if (ans.fr == tmp[i].fr+1+mx){
                xixi.pb(tmp[i].sc);
                sum += cnt*tmp[i].sc;
                f = max(f,1ll);
            }
            else break;
        }
        if (f==2)ans.sc=sum;
        else if (f==1){
            ans.sc+=sum;
        }

    }
}

pii merg(pii x,pii y){
	if(x.fr>y.fr)
		return x;
	if(y.fr>x.fr)
		return y;
	return {x.fr,x.sc+y.sc};
}

main(){

    int n,i,j;
    cin>>n;
    for (i=1;i<=n;++i){
        int x,y;
        cin>>x>>y;
        g[x].pb(y);
        g[y].pb(x);
		gg[x].pb({y,i});
		gg[y].pb({x,i});
    }
    dfs_cycle(1,0);
    int m = cycle.size();
    if (m == n){
        cout <<n;
        ret 0;
    }
    for (i=0;i<m;++i)
        bosh[cycle[i]] = 1;
    for (i=0;i<m;++i){
        dfs_diametr(cycle[i],0);
//        cout <<cycle[i]<<"-"<<dlina[cycle[i]]<<" ";
//        cout <<colichestvo[cycle[i]]<<"\n";
    }

    int sz = m;
    vector <int>otvet;
    for (i=0;i<m;++i)
        otvet.pb(cycle[i]);

    for (i=0;i<m-1;++i)
        otvet.pb(cycle[i]);

    for (i=0;i<otvet.size();++i){
        int vershina = otvet[i];

    }







	vector<pii>gg;
	for (i=0;i<m;++i)
		gg.pb({dlina[cycle[i]],colichestvo[cycle[i]]});



    map <int,int> mp;
	int p=0;
	for(int i=0;i<sz-1;i++){
		while(p < sz and p+p <= sz+i+i)
			mp[gg[p].fr+p]+=gg[p].sc,p++;
		mp[gg[i].fr+i] -= gg[i].sc;
		if(!mp[gg[i].fr+i])
			mp.erase(gg[i].fr+i);
		pii tmp=*mp.rbegin();
		ans = merg(ans,{tmp.fr + gg[i].fr-i, gg[i].sc * tmp.sc});
	}

	p=sz-1;
	mp.clear();

	for(int i=sz-1;i>=0;i--){
		while(p+p>=sz+i+i)
			mp[gg[p].fr+sz-p]+=gg[p].sc,p--;
		if(mp.size()){
			pii tmp=*mp.rbegin();
			ans=merg(ans,{tmp.fr+gg[i].fr+i,gg[i].sc*tmp.sc});
		}
	}





    for (i=0;i<m;++i){
        posledniy_dfs(cycle[i],0);
    }
    cout <<ans.sc;

}
/*
16
1 2
2 3
3 4
4 5
5 6
6 7
7 8
8 9
6 10
10 11
10 12
5 13
2 14
2 15
15 16
7 1


10
1 2
2 3
3 4
4 7
3 5
3 8
5 6
8 9
9 10
3 1
*/

Compilation message (stderr)

shymbulak.cpp: In function 'void dfs_cycle(long long int, long long int)':
shymbulak.cpp:32:15: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   32 |     for (i=0;i<g[x].size();++i){
      |              ~^~~~~~~~~~~~
shymbulak.cpp:36:23: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   36 |             for (j=0;j<v.size();++j){
      |                      ~^~~~~~~~~
shymbulak.cpp: In function 'void dfs_diametr(long long int, long long int)':
shymbulak.cpp:57:15: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   57 |     for (i=0;i<g[x].size();++i){
      |              ~^~~~~~~~~~~~
shymbulak.cpp:68:15: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<std::pair<long long int, long long int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   68 |     for (i=1;i<tmp.size();++i){
      |              ~^~~~~~~~~~~
shymbulak.cpp: In function 'void posledniy_dfs(long long int, long long int)':
shymbulak.cpp:98:15: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   98 |     for (i=0;i<g[x].size();++i){
      |              ~^~~~~~~~~~~~
shymbulak.cpp:111:19: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<std::pair<long long int, long long int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  111 |         for (i=1;i<tmp.size();++i){
      |                  ~^~~~~~~~~~~
shymbulak.cpp:122:19: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  122 |         for (i=0;i<xixi.size();++i){
      |                  ~^~~~~~~~~~~~
shymbulak.cpp:137:19: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<std::pair<long long int, long long int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  137 |         for (i=1;i<tmp.size();++i){
      |                  ~^~~~~~~~~~~
shymbulak.cpp:135:19: warning: unused variable 'bla' [-Wunused-variable]
  135 |         int sum=0,bla=0;
      |                   ^~~
shymbulak.cpp: At global scope:
shymbulak.cpp:165:6: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
  165 | main(){
      |      ^
shymbulak.cpp: In function 'int main()':
shymbulak.cpp:199:15: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  199 |     for (i=0;i<otvet.size();++i){
      |              ~^~~~~~~~~~~~~
shymbulak.cpp:200:13: warning: unused variable 'vershina' [-Wunused-variable]
  200 |         int vershina = otvet[i];
      |             ^~~~~~~~
shymbulak.cpp:167:13: warning: unused variable 'j' [-Wunused-variable]
  167 |     int n,i,j;
      |             ^

• Subtask 1: 30 / 30
• Subtask 2: 20 / 20
• Subtask 3: 50 / 50