Submission #173331

#	Time	Username	Problem	Language	Result	Execution time	Memory
173331		achibasadzishvili	Hard route (IZhO17_road)	C++14	0 / 100	15 ms	12152 KiB

road

#include<bits/stdc++.h>
#define ll long long
#define f first
#define s second
#define pb push_back
#define N 500005
using namespace std;
ll ans = 0,ansraod = 0;
pair<pair<ll,ll> ,pair<ll,ll> >mx[N];
vector<ll>v[N];
ll n,m,star;
void go(ll x,ll par){
    for(int i=0; i<v[x].size(); i++)
        if(v[x][i] != par)
            go(v[x][i] , x);
    ll cur = -1 , raod = 1 , ind = 0 , wn = -1 , sh = 0;
    for(int i=0; i<v[x].size(); i++)
        if(v[x][i] != par){
            ll to = v[x][i];
            if(mx[to].f.f < cur && mx[to].f.f > wn){
                wn = mx[to].f.f;
            }
            if(mx[to].f.f > cur){
                raod = 0;
                sh = 0;
                wn = cur;
                cur = mx[to].f.f;
            }
            if(mx[to].f.f == cur){
                ind = to;
                sh++;
                raod += mx[to].f.s;
            }
        }
    /*
        mx[x].f.f aris maximaluri sigrme xidan
        mx[x].f.s ki aris aseti wveroebis raodenoba
        mx[x].s.f aris danartis max sigrdze
        mx[x].s.s maxiani danarti ro moipovebodes egetebis raodenoba
    */
    if(ind == 0){
        mx[x].f.f = 1;
        mx[x].f.s = 1;
        mx[x].s.f = 0;
        mx[x].s.s = 1;
        return;
    }
    cur += 1;
    mx[x].f.f = cur;
    mx[x].f.s = raod;
    if(sh > 1){
        mx[x].s.f = cur - 1;
        mx[x].s.s = sh;
        return;
    }
    mx[x].s.f = wn + 1;
    mx[x].s.s = 1;
}
void calc(ll x,ll y,ll gare,ll pir,ll meo){
    //cout << x << "<-->" << y << " " << gare << " " << pir << " " << meo << endl;
    ll namr = max(pir , meo);
    if(gare >= namr){
        namr = gare;
        if(namr * (mx[x].f.f + mx[y].f.f) > ans){
            ans = namr * (mx[x].f.f + mx[y].f.f);
            ansraod = 0;
        }
        if(namr * (mx[x].f.f + mx[y].f.f) == ans){
            ansraod += mx[x].f.s * mx[y].f.s;
        }
        return;
    }
    if(pir == meo){
        if(namr * (mx[x].f.f + mx[y].f.f) > ans){
            ans = namr * (mx[x].f.f + mx[y].f.f);
            ansraod = 0;
        }
        if(namr * (mx[x].f.f + mx[y].f.f) == ans){
            ansraod += mx[x].s.s * mx[y].f.s + mx[y].s.s * mx[x].f.s;
            ansraod -= mx[x].s.s * mx[y].s.s;
        }
        return;
    }
    if(mx[x].s.f == namr){
        if(namr * (mx[x].f.f + mx[y].f.f) > ans){
            ans = namr * (mx[x].f.f + mx[y].f.f);
            ansraod = 0;
        }
        if(namr * (mx[x].f.f + mx[y].f.f) == ans){
            ansraod += mx[x].s.s * mx[y].f.s;
        }
        return;
    }
    if(mx[y].s.f == namr){
        if(namr * (mx[x].f.f + mx[y].f.f) > ans){
            ans = namr * (mx[x].f.f + mx[y].f.f);
            ansraod = 0;
        }
        if(namr * (mx[x].f.f + mx[y].f.f) == ans){
            ansraod += mx[y].s.s * mx[x].f.s;
        }
        return;
    }
}
void solve(ll x,ll par,ll zed){
    //cout << x << " " << par << " " << zed << endl;
    ll mx1 = -1,mx2 = -1,ind = 0;
    for(int i=0; i<v[x].size(); i++)
        if(v[x][i] != par){
            int to = v[x][i];
            if(mx[to].f.f >= mx1){
                ind = to;
                mx2 = mx1;
                mx1 = mx[to].f.f;
            }
            else if(mx[to].f.f > mx2)mx2 = mx[to].f.f;
        }
    mx1++;
    mx2++;
    for(int i=0; i<v[x].size(); i++)
        if(v[x][i] != par){
            int to = v[x][i];
            ll nex = 0;
            if(to == ind)
                nex = max(zed + 1 , mx2);
            else nex = max(zed + 1 , mx1);
            solve(to , x , nex);
        }
    if((int)v[x].size() - (x != star) < 2){
        return;
    }
    ll gan = 0 , sum = 0 , minus = 0;
    for(int i=0; i<v[x].size(); i++)
        if(v[x][i] != par){
            int to = v[x][i];
            if(mx[to].f.f == mx[x].f.f - 1){
                gan++;
                sum += mx[to].f.s;
                minus += (mx[to].f.s - 1) * mx[to].f.s / 2 + mx[to].f.s;
            }
        }
    if(gan > 2){
        ll namr = max(mx[x].f.f - 1 , zed);
        //cout << namr << " " << sum << "<<<<<" << minus << endl;
        if(namr * 2LL * (mx[x].f.f - 1) > ans){
            ans = namr * 2LL * (mx[x].f.f - 1);
            ansraod = 0;
        }
        if(namr * 2LL * (mx[x].f.f - 1) == ans){
            ansraod += (sum * sum - minus) / 2;
        }
        return;
    }
    if(gan == 2){
        ll ind1 = 0 , ind2 = 0 , mxx = -1;
        for(int i=0; i<v[x].size(); i++)
            if(v[x][i] != par){
                int to = v[x][i];
                if(mx[to].f.f == mx[x].f.f - 1){
                    if(!ind1){
                        ind1 = to;
                        continue;
                    }
                    ind2 = to;
                    continue;
                }
                mxx = max(mxx , mx[to].f.f);
            }
        ll namr = max(mx[ind1].s.f , mx[ind2].s.f);
        ll gar = max(mxx , zed);
        calc(ind1 , ind2 , gar , mx[ind1].s.f , mx[ind2].s.f);
        ll ne = -1 , in = 0 , ram = 0;
        for(int i=0; i<v[x].size(); i++){
            if(v[x][i] != par){
                int to = v[x][i];
                if(to == ind1 || to == ind2)continue;
                if(mx[to].f.f > ne){
                    ne = mx[to].f.f;
                    in = to;
                    ram = 0;
                }
                if(ne == mx[to].f.f){
                    ram++;
                }
            }
        }
        if(ne == -1)return;
        if(max(mx[ind1].f.f , zed) * (mx[ind1].f.f + ne) > ans){
            ans = max(mx[ind1].f.f , zed) * (mx[ind1].f.f + ne);
            ansraod = 0;
        }
        if(max(mx[ind1].f.f , zed) * (mx[ind1].f.f + ne) == ans){
            ansraod += 2LL * ram;
        }
        return;
    }
    ll f = 0;
    for(int i=0; i<v[x].size(); i++){
        if(v[x][i] != par){
            int to = v[x][i];
            if(mx[to].f.f == mx[x].f.f - 1){
                f = to;
                break;
            }
        }
    }
    ll m1 = -1 , m2 = -1, mi = 0;
    for(int i=0; i<v[x].size(); i++){
        if(v[x][i] != par){
            int to = v[x][i];
            if(mx[to].f.f != mx[x].f.f - 1){
                if(mx[to].f.f >= m1){
                    m2 = m1;
                    mi = to;
                    m1 = mx[to].f.f;
                }
                else if(mx[to].f.f > m2)m2 = mx[to].f.f;
            }
        }
    }
    for(int i=0; i<v[x].size(); i++){
        if(v[x][i] != par){
            int to = v[x][i];
            if(mx[to].f.f == m1){
                ll gar = max(zed , m2);
                calc(f , to , gar , mx[f].s.f , mx[to].s.f);
            }
        }
    }
    ll ne = -1 , ni = 0 , inn = 0;
    for(int i=0; i<v[x].size(); i++){
        if(v[x][i] != par){
            int to = v[x][i];
            if(to == f)continue;
            if(mx[to].f.f > ne){
                ne = mx[to].f.f;
                inn = to;
                ni = 0;
            }
            if(mx[to].f.f == ne){
                ni++;
            }
        }
    }
    if(ni <= 0)return;
    if(ni > 1){
        if(max(mx[f].f.f , zed) * (ne + ne) > ans){
            ans = max(mx[f].f.f , zed) * (ne + ne);
            ansraod = 0;
        }
        if(max(mx[f].f.f , zed) * (ne + ne) == ans){
            ansraod += ni * (ni - 1) / 2;
        }
        return;
    }
    ll po = -1 , pi = 0;
    for(int i=0; i<v[x].size(); i++){
        if(v[x][i] != par){
            int to = v[x][i];
            if(to == inn || to == f)continue;
            if(mx[to].f.f > po){
                po = mx[to].f.f;
                pi = 0;
            }
            if(mx[to].f.f == po){
                pi++;
            }
        }
    }
    if(po <= 0)return;
    if(max(mx[f].f.f , zed) * (po + ne) > ans){
        ans = max(mx[f].f.f , zed) * (po + ne);
        ansraod = 0;
    }
    if(max(mx[f].f.f , zed) * (po + ne) == ans){
        ansraod += pi;
    }
}
int main(){
    ios::sync_with_stdio(false);
    cin >> n;
    
    if(n == 2){
        cout << 0 << " " << 1 << '\n';
        return 0;
    }
    
    for(int i=1; i<n; i++){
        int x,y;
        cin >> x >> y;
        v[x].pb(y);
        v[y].pb(x);
    }
    ll kk = 0;
    for(int i=1; i<=n; i++)
        if((int)v[i].size() > 1){
            star = i;break;
            kk++;
        }
    //cout << star << endl;
    go(star , 0);
    
    solve(star , 0 , 0);
    /*if(ans == 0){
        cout << 0 << " " << kk * (kk - 1) / 2 << '\n';
        return 0;
    }*/
    cout << ans << " " << ansraod << '\n';
    
    return 0;
}

Compilation message (stderr)

road.cpp: In function 'void go(long long int, long long int)':
road.cpp:13:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for(int i=0; i<v[x].size(); i++)
                  ~^~~~~~~~~~~~
road.cpp:17:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for(int i=0; i<v[x].size(); i++)
                  ~^~~~~~~~~~~~
road.cpp: In function 'void solve(long long int, long long int, long long int)':
road.cpp:108:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for(int i=0; i<v[x].size(); i++)
                  ~^~~~~~~~~~~~
road.cpp:120:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for(int i=0; i<v[x].size(); i++)
                  ~^~~~~~~~~~~~
road.cpp:133:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for(int i=0; i<v[x].size(); i++)
                  ~^~~~~~~~~~~~
road.cpp:156:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
         for(int i=0; i<v[x].size(); i++)
                      ~^~~~~~~~~~~~
road.cpp:173:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
         for(int i=0; i<v[x].size(); i++){
                      ~^~~~~~~~~~~~
road.cpp:169:12: warning: unused variable 'namr' [-Wunused-variable]
         ll namr = max(mx[ind1].s.f , mx[ind2].s.f);
            ^~~~
road.cpp:172:22: warning: variable 'in' set but not used [-Wunused-but-set-variable]
         ll ne = -1 , in = 0 , ram = 0;
                      ^~
road.cpp:198:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for(int i=0; i<v[x].size(); i++){
                  ~^~~~~~~~~~~~
road.cpp:208:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for(int i=0; i<v[x].size(); i++){
                  ~^~~~~~~~~~~~
road.cpp:221:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for(int i=0; i<v[x].size(); i++){
                  ~^~~~~~~~~~~~
road.cpp:231:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for(int i=0; i<v[x].size(); i++){
                  ~^~~~~~~~~~~~
road.cpp:257:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for(int i=0; i<v[x].size(); i++){
                  ~^~~~~~~~~~~~
road.cpp:207:27: warning: variable 'mi' set but not used [-Wunused-but-set-variable]
     ll m1 = -1 , m2 = -1, mi = 0;
                           ^~

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