Submission #1216028

#	Time	Username	Problem	Language	Result	Execution time	Memory
1216028		M_SH_O	Hard route (IZhO17_road)	C++20	0 / 100	0 ms	328 KiB

road

#include <bits/stdc++.h>
//#include "grader.h"
/*#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>*/

#define ll long long
#define ll1 long long
#define ull unsigned long long
#define dou long double
#define str string
#define vll vector<ll>
#define vi vector<int>
#define pll pair<ll, ll>
#define vpll vector<pll>
#define vbool vector<bool>
#define vstr vector<str>
#define vvll vector<vll>
#define pb push_back
#define pf push_front
#define endl "\n"
#define fr first
#define se second
// #define sortcmp(a) sort(a.begin(), a.end(), cmp)
#define sort(a) sort(a.begin(), a.end())
#define all(a) a.begin(), a.end()
#define reverse(a) reverse(a.begin(), a.end())
#define speed ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0)
#define INF 1000000000000000000
#define ordered_set tree<pll, null_type, less<pll>, rb_tree_tag, tree_order_statistics_node_update>

using namespace std;
//using namespace __gnu_pbds;

mt19937 rng(1488);
ll randll(ll l, ll r){
    return uniform_int_distribution<ll>(l, r)(rng);
}

/*vector<map<ll, vll>> s;
vll p;

ll find(ll v) {
    if (p[v] == v) return v;
    return p[v] = find(p[v]);
}

void unite(ll a, ll b) {
    a = find(a);
    b = find(b);

    if (a == b) return;
    if (s[a].size() < s[b].size()) {
        p[a] = b;
        for (auto i : s[a]) {
            for (int j : i.se) {
                s[b][i.fr].pb(j);
            }
        }
        s[a].clear();
    }
    else {
        p[b] = a;
        for (auto i : s[b]) {
            for (int j : i.se) {
                s[a][i.fr].pb(j);
            }
        }
        s[b].clear();
    }
}

vll tree1, d;

void push(ll v, ll tl, ll tr) {
    if (tl == tr) return;
    tree1[v*2] += d[v];
    tree1[v*2+1] += d[v];
    d[v*2] += d[v];
    d[v*2+1] += d[v];
    d[v] = 0;
    tree1[v] = tree1[v*2]+tree1[v*2+1];
}

void bt(ll v, ll tl, ll tr, vll& a) {
    if (tl == tr) {
        tree1[v] = a[tl];
        return;
    }

    ll tm = (tl+tr)/2;
    bt(v*2, tl, tm, a);
    bt(v*2, tm+1, tr, a);

    tree1[v] = tree1[v*2]+tree1[v*2+1];
}

ll get(ll l, ll r, ll v, ll tl, ll tr) {
    if (l <= tl && tr <= r) return tree1[v];
    if (tl > r || tr < l) return 0;

    ll tm = (tl+tr)/2;
    push(v, tl, tr);
    return get(l, r, v*2, tl, tm)+get(l, r, v*2+1, tm+1, tr);
}

void update(ll l, ll r, ll val, ll v, ll tl, ll tr) {
    if (l <= tl && tr <= r) {
        tree1[v] += val;
        d[v] += val;
        push(v, tl, tr);
        return;
    }
    if (tl > r || tr < l) return;

    ll tm = (tl+tr)/2;
    push(v, tl, tr);

    update(l, r, val, v*2, tl, tm);
    update(l, r, val, v*2+1, tm+1, tr);

    tree1[v] = tree1[v*2]+tree1[v*2+1];
}*/

vvll g;
vpll dp;

void dfs(ll v, ll p = -1) {
    if (g[v].size() == 1) dp[v] = {0, 1};

    for (int i : g[v]) {
        if (i == p) continue;
        dfs(i, v);
        if (dp[i].fr > dp[v].fr) {
            dp[v] = {dp[i].fr, 0};
        }
        if (dp[i].fr == dp[v].fr) dp[v].se += dp[i].se;
    }
    dp[v].fr ++;
}

int main() {
    ll n;
    cin >> n;
    g.resize(n+7);

    for (int i = 0 ; i < n-1; i ++) {
        ll a, b;
        cin >> a >> b;
        g[a].pb(b);
        g[b].pb(a);
    }

    ll maxl = 0, res = 1;

    for (int i = 1; i <= n; i ++) {
        if (g[i].size() < 3) continue;
        dp.clear();
        dp.resize(n+7, {0, 0});
        dfs(i);
        vpll v;
        for (int j : g[i]) {
            v.pb({dp[j]});
        }

        sort(v);

        ll cnt = 0;
        ll k = v.size();
        if (v[k-1].fr == v[k-3].fr) {
            ll k1 = 0;
            for (int j = k-1; j >= 0; j --) {
                if (v[j].fr != v[k-1].fr) break;
                k1 += v[j].se;
            }

            for (int j = k-1; j >= 0; j --) {
                if (v[j].fr != v[k-1].fr) break;
                cnt += (k1-v[j].se)*(k1-v[j].se-1)/2;
            }
        }
        else if (v[k-1].fr == v[k-2].fr) {
            ll k1 = 0;
            for (int j = k-1; j >= 0; j --) {
                if (v[j].fr != v[k-3].fr) break;
                k1 += v[j].se;
            }

            cnt = k1+v[k-1].se+v[k-2].se;
        }
        else if (v[k-2].fr == v[k-3].fr) {
            ll k1 = 0;
            for (int j = k-2; j >= 0; j --) {
                if (v[j].fr != v[k-2].fr) break;
                k1 += v[j].se;
            }

            cnt = k1*(k1-1)/2;
        }
        else {
            ll k1 = 0;
            for (int j = k-1; j >= 0; j --) {
                if (v[j].fr != v[k-3].fr) break;
                k1 += v[j].se;
            }

            cnt = k1;
        }
        /*cout << i << endl;
        for (auto j : v) {
            cout << j.fr << ' ' << j.se << endl;
        }*/


        if (v[k-1].fr*(v[k-2].fr+v[k-3].fr) > maxl) {
            maxl = v[k-1].fr*(v[k-2].fr+v[k-3].fr);
            res = 0;
        }
        if (v[k-1].fr*(v[k-2].fr+v[k-3].fr) == maxl) {
            res += cnt;
        }
    }

    cout << maxl << ' ' << res << endl;
}

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