제출 #931094

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
931094		Whisper	Papričice (COCI20_papricice)	C++17	110 / 110	170 ms	24320 KiB

papricice

#include <bits/stdc++.h>

using namespace std;
using ll = long long;

#define int long long
#define FOR(i, a, b) for ( int i = a ; i <= b ; i++ )
#define FORD(i, a, b) for (int i = b; i >= a; i --)
#define REP(i, n) for (int i = 0; i < n; ++i)
#define REPD(i, n) for (int i = n - 1; i >= 0; --i)
#define pii pair<int , int>
#define Lg(x) 31 - __builtin_clz(x)

#define MASK(i) (1LL << (i))
#define BIT(x, i) (((x) >> (i)) & 1)

constexpr ll LINF = (1ll << 60);
constexpr int INF = (1ll << 30);
constexpr int MAX = 2e5 + 5;
constexpr int Mod = 1e9 + 7;
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());

void setupIO(){
    #define name "Whisper"
    //Phu Trong from Nguyen Tat Thanh High School for gifted student
    srand(time(NULL));
    cin.tie(nullptr)->sync_with_stdio(false); cout.tie(nullptr);
    //freopen(name".inp", "r", stdin);
    //freopen(name".out", "w", stdout);
    cout << fixed << setprecision(10);
}

template <class X, class Y>
    bool minimize(X &x, const Y &y){
        X eps = 1e-9;
        if (x > y + eps) {x = y; return 1;}
        return 0;
    }

template <class X, class Y>
    bool maximize(X &x, const Y &y){
        X eps = 1e-9;
        if (x + eps < y) {x = y; return 1;}
        return 0;
    }

int numNode;
vector<int> adj[MAX];
int sz[MAX];
void reSubsize(int u, int p = -1){
    sz[u] = 1;
    for (auto&v : adj[u]) if(v ^ p){
        reSubsize(v, u);
        sz[u] += sz[v];
    }
}
int optimize(int a, int b, int c){
    return max({a, b, c}) - min({a, b, c});
}
int ans = INF;
set<int> a, b;
vector<int> compute(set<int>&x, int v){
    auto it = x.lower_bound(v);
    vector<int> res;
    if (it != x.end()) res.push_back(*it);
    if (it != x.begin()) res.push_back(*(--it));
    return res;
}
void dfs(int u, int p){
    for (int szA : compute(a, (numNode + sz[u]) / 2)){
        minimize(ans, optimize(sz[u], szA - sz[u], numNode - szA));
    }
    for (int szB : compute(b, (numNode - sz[u]) / 2)){
        minimize(ans, optimize(sz[u], szB, numNode - sz[u] - szB));
    }
    a.insert(sz[u]);
    for (auto&v : adj[u]) if(v ^ p){
        dfs(v, u);
    }
    a.erase(sz[u]);
    b.insert(sz[u]);
}
void Whisper(){
    cin >> numNode;
    for (int i = 1; i < numNode; ++i){
        int u, v; cin >> u >> v;
        adj[u].push_back(v);
        adj[v].push_back(u);
    }
    reSubsize(1);
    dfs(1, 0);
    cout << ans;
}


signed main(){
    setupIO();
    int Test = 1;
//    cin >> Test;
    for ( int i = 1 ; i <= Test ; i++ ){
        Whisper();
        if (i < Test) cout << '\n';
    }
}

• Subtask 1: 15 / 15
• Subtask 2: 35 / 35
• Subtask 3: 60 / 60