Submission #495229

#	Time	Username	Problem	Language	Result	Execution time	Memory
495229		Karliver	Hard route (IZhO17_road)	C++17	0 / 100	10 ms	12216 KiB

road

    
#include <bits/stdc++.h>

#define FIXED_FLOAT(x)  std::fixed <<std::setprecision(20) << (x)
#define all(v) (v).begin(), (v).end()
using namespace  std;
#define forn(i,n) for (int i = 0; i < (n); ++i)
#define rforn(i, n) for(int i = (n) - 1;i >= 0;--i)
#define sz(x) (int)x.size()
#define ff first
#define se second
#define mp make_pair
using ll = long long;
int mod = (ll)1e9 + 7;
const int INF = 1e9 + 1;
const int N = 5e5 + 100;
const double eps = 1e-7;

template <class T> using V = vector<T>;  
template <class T> using VV = V<V<T>>;  
template<class T, size_t SZ> using AR = array<T, SZ>;
template<class T> using PR = pair<T, T>;
template <typename XPAX>
bool ckma(XPAX &x, XPAX y) {
    return (x < y ? x = y, 1 : 0);
}
template <typename XPAX>
bool ckmi(XPAX &x, XPAX y) {
    return (x > y ? x = y, 1 : 0);
}
V<int> g[N];
int dep[N];
PR<int> m1[N], m2[N];
int w[N];
map<ll, int> sp;
void caldep(int v, int p) {

    for(auto c : g[v]) {
        if(c == p)continue;
        dep[c]= dep[v]+1;
        caldep(c, v);
        if(m1[c].ff+1 >m1[v].ff) {
            m1[v] = {m1[c].ff+1,c};
        }
        else if(m1[c].ff+1 > m2[v].ff) {
            m2[v] = {m1[c].ff+1,c};
        }
    }
}
void dfs1(int v, int p) {
    ckma(w[v], dep[v]);
    if(v != p) {
        ckma(w[v], (m1[p].se == v ? m2[p].ff : m1[p].ff)+1);
        ckma(w[v], w[p]+1);
    }

    for(auto c : g[v]) {
        if(c==p)continue;
        dfs1(c, v);
    }

}

void dfs2(int v,int p) {

    V<int> ds;
    for(auto c : g[v]) {
        if(c==p) {
            continue;
        }
        dfs2(c, v);
        ds.push_back(m1[c].ff+1);
    }
    sort(all(ds));

    if(sz(ds)>=2 && v!= p) {
        int x = ds.back(), y = ds[sz(ds)-2];
        ll mx = w[v];
        ll cnt1 = count(all(ds), x), cnt2 = count(all(ds), y);
        ll ad = 0;
        if(x==y)
            ad = cnt1 * (cnt1-1)/2;
        else
            ad = cnt1*cnt2;
        ll lstsm = x+y;
        sp[mx*lstsm] += ad;
    }
    if(sz(ds) >= 3) {
        ll x = ds.back(), y = ds[sz(ds)-2], z = ds[sz(ds)-1];
        ll lstsm = x+y;
        ll ad = 0;
        ll cnt1 = count(all(ds),x);
        ll cnt2 = count(all(ds),z);
        if(x==z) {
            ad = cnt1 * (cnt1 -1) / 2 * (cnt1-2);
        }
        else if(x==y) {
            ad = cnt2 * (cnt1-1)/2 * cnt2;
        }
        else
            ad = cnt2;
        sp[lstsm*ds[sz(ds)-3]] += ad;
    }

}



void __print(int x) {cerr << x;}
void __print(long x) {cerr << x;}
void __print(long long x) {cerr << x;}
void __print(unsigned x) {cerr << x;}
void __print(unsigned long x) {cerr << x;}
void __print(unsigned long long x) {cerr << x;}
void __print(float x) {cerr << x;}
void __print(double x) {cerr << x;}
void __print(long double x) {cerr << x;}
void __print(char x) {cerr << '\'' << x << '\'';}
void __print(const char *x) {cerr << '\"' << x << '\"';}
void __print(const string &x) {cerr << '\"' << x << '\"';}
void __print(bool x) {cerr << (x ? "true" : "false");}

template<typename T, typename V>
void __print(const pair<T, V> &x) {cerr << '{'; __print(x.first); cerr << ','; __print(x.second); cerr << '}';}
template<typename T>
void __print(const T &x) {int f = 0; cerr << '{'; for (auto &i: x) cerr << (f++ ? "," : ""), __print(i); cerr << "}";}
void _print() {cerr << "]\n";}
template <typename T, typename... V>
void _print(T t, V... v) {__print(t); if (sizeof...(v)) cerr << ", "; _print(v...);}
#define debug(x...) cerr << "[" << #x << "] = ["; _print(x)
void solve() {


    int n;
    cin >> n;

    
    forn(i, n -1) {
        int a, b;
        cin >> a >> b;
        --a;--b;
        g[a].push_back(b);
        g[b].push_back(a);
    }

    int root = 0;
    forn(i, n) {
        if(sz(g[i])>1) {
            root = i;
            break;
        }
    }
    caldep(root, root);

    dfs1(root, root);
    dfs2(root, root);
    debug(w[4]);
    if(!sz(sp))
        sp[0]++;
    auto it = sp.rbegin();
    //debug(sp);
    cout << it->first << ' ' << it->second << '\n';


}
void test_case() {
    int t;
    cin >> t;
    forn(p, t) {

        //cout << "Case #" << p + 1 << ": ";
        solve();
    }
}
int main() {

    ios::sync_with_stdio(false);
    cin.tie(0);

    solve();

}

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