Submission #799654

#	Time	Username	Problem	Language	Result	Execution time	Memory
799654		farhan132	Hard route (IZhO17_road)	C++17	100 / 100	635 ms	151704 KiB

road

/***Farhan132***/
// #pragma GCC optimize("Ofast,fast-math")
// #pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,avx2,fma")
// #pragma GCC optimization ("unroll-loops")

#include <bits/stdc++.h>
 
using namespace std;
 
typedef long long ll;
typedef double dd;
typedef pair<ll , ll> ii;
typedef tuple < ll,  ll, ll > tp;
 
#define ff first
#define ss second
#define pb push_back
#define in insert
#define bug printf("**!\n")
#define mem(a , b) memset(a, b ,sizeof(a))
#define front_zero(n) __builtin_clz(n)
#define back_zero(n) __builtin_ctzll(n)
#define total_one(n) __builtin_popcount(n)
#define clean fflush(stdout)
 
const ll mod =  (ll) 998244353;
// const ll mod =  (ll) 1e9 + 7;
//const ll INF = numeric_limits<ll>::max()-1;
const ll INF = (ll)2e18;
 
// ll dx[]={0,1,0,-1};
// ll dy[]={1,0,-1,0};
// ll dxx[]={0,1,0,-1,1,1,-1,-1};
// ll dyy[]={1,0,-1,0,1,-1,1,-1};
 
mt19937 rng(chrono::system_clock::now().time_since_epoch().count());
 
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace __gnu_pbds;
 
template <typename T> using ordered_set = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;

const ll N = 5e5 + 5;

ll dist[N], c[N];
vector < ll > v[N];

void dfs(ll s, ll p){
    dist[s] = 0; c[s] = 1;
    for(auto u : v[s]){
        if(u - p){
            dfs(u, s);
            if(dist[u] + 1 > dist[s]){
                dist[s] = dist[u] + 1;
                c[s] = c[u];
            }else{
                if(dist[u] + 1 == dist[s]) c[s] += c[u];
            }
        }
    }
    return;
}

ii ans = {0, 1};

ll knap(vector < ll > c, ll k){
    ll S = 0, ans = 0;
    for(auto u : c){
        ans -= (u * (u - 1)) / 2;
        S += u;
    }
    ans += (S * (S - 1)) / 2;
    return ans;
}

void calc(ll s, ll p, ii best){
    vector < ii > paths;
    if( (!p && v[s].size() == 1) || best.ff > 0) paths.pb(best);
    for(auto u : v[s]){
        if(u - p) paths.pb({dist[u] + 1, c[u]});
    }
    sort(paths.rbegin(), paths.rend());
    if(paths.size() >= 3){
        ll res = (paths[0].ff * (paths[1].ff + paths[2].ff));
        ll cnt = 0;
        if(paths[0].ff == paths[2].ff){
            vector < ll > C;
            for(auto [x, y] : paths){
                if(x == paths[0].ff) C.pb(y);
            }
            cnt = knap(C, 2);
        }else{
            if(paths[0].ff == paths[1].ff){
                for(auto [x, y] : paths){
                    if(x == paths[2].ff) cnt += (paths[0].ss + paths[1].ss) * y;
                }
            }else{
                if(paths[1].ff == paths[2].ff){
                    vector < ll > C;
                    for(auto [x, y] : paths){
                        if(x == paths[1].ff) C.pb(y);
                    }
                    cnt = knap(C, 2);
                }else{
                    for(auto [x, y] : paths){
                        if(x == paths[2].ff) cnt += (paths[1].ss) * y;
                    }
                }  
            }
        }
        if(res > ans.ff){
            ans = {res, cnt};
        }else{
            if(res == ans.ff) ans.ss += cnt;
        }
    }
    ll c1 = 0, c2 = 0;
    for(auto [x, y] : paths){
        if(paths.size() > 0 && paths[0].ff == x) c1 += y;
        if(paths.size() > 1 && paths[1].ff == x) c2 += y;
    }
    for(auto u : v[s]){
        if(u - p){
            if(paths[0].ff == dist[u] + 1){
                if(c[u] == c1){
                    calc(u, s, {paths[1].ff + 1, c2});
                } else {
                    calc(u, s, {paths[0].ff + 1, c1 - c[u]});
                }
            }else{
                calc(u, s, {paths[0].ff + 1, c1});
            }
        }
    }
    return;
}

void solve(){

    ll n; cin >> n;

    for(ll i = 1; i < n; i++){
        ll x, y; cin >> x >> y;
        v[x].pb(y);
        v[y].pb(x);
    }


    dfs(1, 0);
    calc(1, 0, {0, 1});

    cout << ans.ff << ' ' << ans.ss << '\n';
    
   return;
}

int main() {

    #ifdef LOCAL
        freopen("in.txt", "r", stdin);
        freopen("out.txt", "w", stdout);
        auto start_time = clock();
    #else
         // freopen("subsequence.in", "r", stdin);
         // freopen("subsequence.out", "w", stdout); 
         ios_base::sync_with_stdio(0); cin.tie(NULL); cout.tie(NULL);
    #endif

    //precalc();
 
    ll T = 1, CT = 0;// cin >> T; 
 
    while(T--){
        // cout << "Case #" << ++CT << ": ";
        solve();
    }
    
    #ifdef LOCAL
        auto end_time = clock();
        cerr<< "Execution time: "<<(end_time - start_time)*(int)1e3/CLOCKS_PER_SEC<<" ms\n";
    #endif
 
    return 0;
} 

Compilation message (stderr)

road.cpp: In function 'int main()':
road.cpp:172:15: warning: unused variable 'CT' [-Wunused-variable]
  172 |     ll T = 1, CT = 0;// cin >> T;
      |               ^~

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