結果

問題 No.2677 Minmax Independent Set
コンテスト
ユーザー noya2
提出日時 2024-03-15 22:32:19
言語 C++23
(gcc 13.3.0 + boost 1.87.0)
結果
AC  
実行時間 246 ms / 2,000 ms
コード長 7,578 bytes
コンパイル時間 3,030 ms
コンパイル使用メモリ 268,328 KB
実行使用メモリ 76,704 KB
最終ジャッジ日時 2024-09-30 01:57:22
合計ジャッジ時間 10,317 ms
ジャッジサーバーID
（参考情報） 		judge1 / judge2
このコードへのチャレンジ
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ファイルパターン 結果
sample AC * 3
other AC * 61
権限があれば一括ダウンロードができます

ソースコード

diff # 

#line 2 "/Users/noya2/Desktop/Noya2_library/template/template.hpp"
using namespace std;

#include<bits/stdc++.h>
#line 1 "/Users/noya2/Desktop/Noya2_library/template/inout_old.hpp"
namespace noya2 {

template <typename T, typename U>
ostream &operator<<(ostream &os, const pair<T, U> &p){
    os << p.first << " " << p.second;
    return os;
}
template <typename T, typename U>
istream &operator>>(istream &is, pair<T, U> &p){
    is >> p.first >> p.second;
    return is;
}

template <typename T>
ostream &operator<<(ostream &os, const vector<T> &v){
    int s = (int)v.size();
    for (int i = 0; i < s; i++) os << (i ? " " : "") << v[i];
    return os;
}
template <typename T>
istream &operator>>(istream &is, vector<T> &v){
    for (auto &x : v) is >> x;
    return is;
}

void in() {}
template <typename T, class... U>
void in(T &t, U &...u){
    cin >> t;
    in(u...);
}

void out() { cout << "\n"; }
template <typename T, class... U, char sep = ' '>
void out(const T &t, const U &...u){
    cout << t;
    if (sizeof...(u)) cout << sep;
    out(u...);
}

template<typename T>
void out(const vector<vector<T>> &vv){
    int s = (int)vv.size();
    for (int i = 0; i < s; i++) out(vv[i]);
}

struct IoSetup {
    IoSetup(){
        cin.tie(nullptr);
        ios::sync_with_stdio(false);
        cout << fixed << setprecision(15);
        cerr << fixed << setprecision(7);
    }
} iosetup_noya2;

} // namespace noya2
#line 1 "/Users/noya2/Desktop/Noya2_library/template/const.hpp"
namespace noya2{

const int iinf = 1'000'000'007;
const long long linf = 2'000'000'000'000'000'000LL;
const long long mod998 =  998244353;
const long long mod107 = 1000000007;
const long double pi = 3.14159265358979323;
const vector<int> dx = {0,1,0,-1,1,1,-1,-1};
const vector<int> dy = {1,0,-1,0,1,-1,-1,1};
const string ALP = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
const string alp = "abcdefghijklmnopqrstuvwxyz";
const string NUM = "0123456789";

void yes(){ cout << "Yes\n"; }
void no(){ cout << "No\n"; }
void YES(){ cout << "YES\n"; }
void NO(){ cout << "NO\n"; }
void yn(bool t){ t ? yes() : no(); }
void YN(bool t){ t ? YES() : NO(); }

} // namespace noya2
#line 1 "/Users/noya2/Desktop/Noya2_library/template/utils.hpp"
namespace noya2{

unsigned long long inner_binary_gcd(unsigned long long a, unsigned long long b){
    if (a == 0 || b == 0) return a + b;
    int n = __builtin_ctzll(a); a >>= n;
    int m = __builtin_ctzll(b); b >>= m;
    while (a != b) {
        int mm = __builtin_ctzll(a - b);
        bool f = a > b;
        unsigned long long c = f ? a : b;
        b = f ? b : a;
        a = (c - b) >> mm;
    }
    return a << min(n, m);
}

template<typename T> T gcd_fast(T a, T b){ return static_cast<T>(inner_binary_gcd(abs(a),abs(b))); }

long long sqrt_fast(long long n) {
    if (n <= 0) return 0;
    long long x = sqrt(n);
    while ((x + 1) * (x + 1) <= n) x++;
    while (x * x > n) x--;
    return x;
}

template<typename T> T floor_div(const T n, const T d) {
    assert(d != 0);
    return n / d - static_cast<T>((n ^ d) < 0 && n % d != 0);
}

template<typename T> T ceil_div(const T n, const T d) {
    assert(d != 0);
    return n / d + static_cast<T>((n ^ d) >= 0 && n % d != 0);
}

template<typename T> void uniq(vector<T> &v){
    sort(v.begin(),v.end());
    v.erase(unique(v.begin(),v.end()),v.end());
}

template <typename T, typename U> inline bool chmin(T &x, U y) { return (y < x) ? (x = y, true) : false; }

template <typename T, typename U> inline bool chmax(T &x, U y) { return (x < y) ? (x = y, true) : false; }

template<typename T> inline bool range(T l, T x, T r){ return l <= x && x < r; }

} // namespace noya2
#line 8 "/Users/noya2/Desktop/Noya2_library/template/template.hpp"

#define rep(i,n) for (int i = 0; i < (int)(n); i++)
#define repp(i,m,n) for (int i = (m); i < (int)(n); i++)
#define reb(i,n) for (int i = (int)(n-1); i >= 0; i--)
#define all(v) (v).begin(),(v).end()

using ll = long long;
using ld = long double;
using uint = unsigned int;
using ull = unsigned long long;
using pii = pair<int,int>;
using pll = pair<ll,ll>;
using pil = pair<int,ll>;
using pli = pair<ll,int>;

namespace noya2{

/*　~ (. _________ . /)　*/

}

using namespace noya2;


#line 2 "c.cpp"

#line 2 "/Users/noya2/Desktop/Noya2_library/tree/RerootingDP.hpp"

#line 4 "/Users/noya2/Desktop/Noya2_library/tree/RerootingDP.hpp"

namespace noya2 {

template <class E, class V, E (*merge)(E, E), E (*e)(), E (*put_edge)(V, int), V (*put_vertex)(E, int)>
struct RerootingDP {
    struct edge {
        int to, idx, xdi;
    };
    RerootingDP(int _n = 0) : n(_n) {
        es.resize(n);
    }
    void add_edge(int u, int v, int idx1, int idx2) {
        es[u].push_back({v, idx1, idx2});
        es[v].push_back({u, idx2, idx1});
    }
    vector<V> build(int v = 0) {
        root = v;
        outs.resize(n);
        subdp.resize(n);
        in.resize(n), up.resize(n);
        int tnow = 0;
        dfs(root, -1, tnow);
        return subdp;
    }
    vector<V> reroot() {
        reverse_edge.resize(n);
        reverse_edge[root] = e();
        reverse_dp.resize(n);
        answers.resize(n);
        bfs(root);
        return answers;
    }
    V get(int r, int v) {
        if (r == v) return answers[r];
        if (!(in[v] < in[r] && up[r] <= up[v])) return subdp[v];
        int le = 0, ri = outs[v].size();
        while (ri - le > 1) {
            int md = (le + ri) / 2;
            if (in[es[v][md].to] <= in[r])
                le = md;
            else
                ri = md;
        }
        return reverse_dp[es[v][le].to];
    }
    const vector<edge> &operator[](int idx) const {
        return es[idx];
    }

  private:
    int n, root;
    vector<vector<edge>> es;
    vector<vector<E>> outs;
    vector<E> reverse_edge;
    vector<V> subdp, reverse_dp, answers;
    vector<int> in, up;
    void dfs(int v, int p, int &t) {
        E val = e();
        in[v] = t++;
        for (auto &u : es[v]) {
            if (u.to == p && u.to != es[v].back().to) swap(u, es[v].back());
            if (u.to == p) continue;
            dfs(u.to, v, t);
            E nval = put_edge(subdp[u.to], u.idx);
            outs[v].emplace_back(nval);
            val = merge(val, nval);
        }
        subdp[v] = put_vertex(val, v);
        up[v] = t;
    }
    void bfs(int v) {
        int siz = outs[v].size();
        vector<E> lui(siz + 1), rui(siz + 1);
        lui[0] = e(), rui[siz] = e();
        for (int i = 0; i < siz; i++) lui[i + 1] = merge(lui[i], outs[v][i]);
        for (int i = siz - 1; i >= 0; i--) rui[i] = merge(outs[v][i], rui[i + 1]);
        for (int i = 0; i < siz; i++) {
            reverse_dp[es[v][i].to] = put_vertex(merge(merge(lui[i], rui[i + 1]), reverse_edge[v]), v);
            reverse_edge[es[v][i].to] = put_edge(reverse_dp[es[v][i].to], es[v][i].xdi);
            bfs(es[v][i].to);
        }
        answers[v] = put_vertex(merge(lui[siz], reverse_edge[v]), v);
    }
};

}  // namespace noya2
#line 4 "c.cpp"

pii op(pii a, pii b){
    return pii(a.first+b.first,a.second+b.second);
}
pii e(){
    return pii(0,0);
}
pii pute(pii x, int){
    return pii(max(x.first,x.second),x.first);
}
pii putv(pii x, int){
    return pii(x.first,x.second+1);
}

void solve(){
    int n; in(n);
    RerootingDP<pii,pii,op,e,pute,putv> g(n);
    rep(i,n-1){
        int u, v; in(u,v); u--, v--;
        g.add_edge(u,v,-1,-1);
    }
    g.build();
    int ans = iinf;
    for (auto x : g.reroot()){
        chmin(ans,x.second);
    }
    out(ans);
}

int main(){
    int t = 1; //in(t);
    while (t--) { solve(); }
}
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