oj.uz

답안 #543477

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
543477 2022-03-30T17:36:47 Z SavicS 관광지 (IZhO14_shymbulak) C++17
100 / 100
 106 ms 17688 KB 
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
#include <bits/stdc++.h>
 
using namespace std;
using namespace __gnu_pbds;
 
typedef long long ll;
typedef long double ld;
 
typedef pair<int,int> pii;
typedef pair<ll,ll> pll;
typedef pair<ld,ld> pdd;
 
#define ff(i,a,b) for(int i = a; i <= b; i++)
#define fb(i,b,a) for(int i = b; i >= a; i--)
#define trav(a,x) for (auto& a : x)
 
#define sz(a) (int)(a).size()
#define pb push_back
#define fi first
#define se second
#define lb lower_bound
#define ub upper_bound
#define all(a) a.begin(), a.end()
#define rall(a) a.rbegin(), a.rend()
 
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());

template<typename T>
using ordered_set = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;

// os.order_of_key(k) the number of elements in the os less than k
// *os.find_by_order(k)  print the k-th smallest number in os(0-based)

const int mod = 1000000007;
const int inf = 1e9 + 5;
const int mxN = 200005; 

int n;

vector<int> g[mxN];

int par[mxN];
int visited[mxN];
vector<int> cyc;
void dfs1(int v, int p){
    visited[v] = 1; par[v] = p;
    for(auto u : g[v]){
        if(u == p)continue;
        if(!visited[u])dfs1(u, v);
        else{
            if(visited[u] == 1){
                for(int A = v; A != par[u]; A = par[A])cyc.pb(A);
            }
        }
    }
    visited[v] = 2;
}

pll cmb(pll a, pll b){
    if(a.fi == b.fi)return {a.fi, a.se + b.se};
    if(a.fi > b.fi)return a;
    if(a.fi < b.fi)return b;
    assert(false);
}

pll dia = {0, 0};

bool was[mxN];
pll dfs2(int v, int duz){
    pll best = {duz, 1}; was[v] = 1;
    for(auto u : g[v]){
        if(!was[u]){
            pll D = dfs2(u, duz + 1);
            dia = cmb(dia, {best.fi + D.fi - 2 * duz, 1ll * best.se * D.se});
            best = cmb(best, D);
        }
    }
    return best;
}

pll ja[mxN];

pll bor[4 * mxN];
void build(int v, int tl, int tr){
    if(tl == tr){
        bor[v] = {ja[tl].fi - tl, ja[tl].se};
        return;
    }
    int mid = (tl + tr) / 2;
    build(v * 2, tl, mid); build(v * 2 + 1, mid + 1, tr);
    bor[v] = cmb(bor[v * 2], bor[v * 2 + 1]);
}

pll kveri(int v, int tl, int tr, int l, int r){
    if(tl > r || l > tr)return {-inf, 0};
    if(tl >= l && tr <= r)return bor[v];
    int mid = (tl + tr) / 2;
    return cmb(kveri(v * 2, tl, mid, l, r), kveri(v * 2 + 1, mid + 1, tr, l, r));
}

int main() {
    cin.tie(0)->sync_with_stdio(0);

    cin >> n;
    ff(i,1,n){
        int u, v;
        cin >> u >> v;
        g[u].pb(v);
        g[v].pb(u);
    }

    dfs1(1, -1);

    for(auto c : cyc)was[c] = 1;

    int M = sz(cyc);
    ff(i,0,M - 1)ja[i] = dfs2(cyc[i], 0);

    int K = M / 2;
    build(1,0,M - 1);

    ff(i,0,M - 1){
        pii L = kveri(1,0,M - 1,max(0,i - K),i - 1);
        pii R = kveri(1,0,M - 1,min(M - 1, i + K - !(M&1)) + 1,M - 1);
        R.fi += M + i, L.fi += i;

        pii X = cmb(L, R);
        dia = cmb(dia, {X.fi + ja[i].fi, 1ll * X.se * ja[i].se});
    
    }

    cout << dia.se << '\n';

    return 0;
}
/*
 
6
1 2
1 3 
2 4 
4 3 
4 5 
4 6

4
1 2
1 3
1 4
4 3
 
// probati bojenje sahovski
*/

Subtask #1
30.0 / 30.0

# 결과 실행 시간 메모리 Grader output
1 Correct 3 ms 4948 KB Output is correct
2 Correct 3 ms 5028 KB Output is correct
3 Correct 3 ms 4948 KB Output is correct
4 Correct 3 ms 4948 KB Output is correct
5 Correct 3 ms 4928 KB Output is correct
6 Correct 3 ms 4948 KB Output is correct
7 Correct 3 ms 4948 KB Output is correct
8 Correct 3 ms 4948 KB Output is correct
9 Correct 2 ms 4948 KB Output is correct
10 Correct 2 ms 4948 KB Output is correct
11 Correct 3 ms 4948 KB Output is correct
12 Correct 2 ms 4948 KB Output is correct
13 Correct 2 ms 4948 KB Output is correct
14 Correct 3 ms 5076 KB Output is correct
15 Correct 4 ms 5088 KB Output is correct

Subtask #2
20.0 / 20.0

# 결과 실행 시간 메모리 Grader output
1 Correct 4 ms 5204 KB Output is correct
2 Correct 3 ms 5076 KB Output is correct
3 Correct 4 ms 5076 KB Output is correct
4 Correct 4 ms 5076 KB Output is correct
5 Correct 6 ms 5204 KB Output is correct
6 Correct 4 ms 5204 KB Output is correct
7 Correct 4 ms 5204 KB Output is correct
8 Correct 4 ms 5204 KB Output is correct
9 Correct 4 ms 5204 KB Output is correct
10 Correct 4 ms 5220 KB Output is correct

Subtask #3
50.0 / 50.0

# 결과 실행 시간 메모리 Grader output
1 Correct 46 ms 8748 KB Output is correct
2 Correct 51 ms 9292 KB Output is correct
3 Correct 64 ms 17688 KB Output is correct
4 Correct 46 ms 9164 KB Output is correct
5 Correct 32 ms 9080 KB Output is correct
6 Correct 106 ms 12300 KB Output is correct
7 Correct 89 ms 10864 KB Output is correct
8 Correct 75 ms 13208 KB Output is correct
9 Correct 75 ms 13364 KB Output is correct
10 Correct 62 ms 14284 KB Output is correct
11 Correct 60 ms 13348 KB Output is correct
12 Correct 81 ms 16192 KB Output is correct