結果

問題 No.1582 Vertexes vs Edges
ユーザー haruki_Kharuki_K
提出日時 2021-07-06 19:12:58
言語 C++17
(gcc 12.3.0 + boost 1.83.0)
結果
AC  
実行時間 235 ms / 2,000 ms
コード長 9,990 bytes
コンパイル時間 2,757 ms
コンパイル使用メモリ 225,572 KB
実行使用メモリ 37,712 KB
最終ジャッジ日時 2024-07-01 12:12:16
合計ジャッジ時間 7,061 ms
ジャッジサーバーID
（参考情報） 		judge1 / judge4
このコードへのチャレンジ
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テストケース

テストケース表示
入力 結果 実行時間
実行使用メモリ
testcase_00 AC 2 ms
6,812 KB
testcase_01 AC 2 ms
6,944 KB
testcase_02 AC 2 ms
6,944 KB
testcase_03 AC 2 ms
6,940 KB
testcase_04 AC 4 ms
6,940 KB
testcase_05 AC 86 ms
35,648 KB
testcase_06 AC 5 ms
6,940 KB
testcase_07 AC 12 ms
7,776 KB
testcase_08 AC 41 ms
18,540 KB
testcase_09 AC 80 ms
31,696 KB
testcase_10 AC 47 ms
21,256 KB
testcase_11 AC 7 ms
6,944 KB
testcase_12 AC 33 ms
15,424 KB
testcase_13 AC 105 ms
22,872 KB
testcase_14 AC 103 ms
22,924 KB
testcase_15 AC 163 ms
30,260 KB
testcase_16 AC 61 ms
16,340 KB
testcase_17 AC 98 ms
22,020 KB
testcase_18 AC 160 ms
36,516 KB
testcase_19 AC 74 ms
23,976 KB
testcase_20 AC 83 ms
20,532 KB
testcase_21 AC 75 ms
19,356 KB
testcase_22 AC 121 ms
32,668 KB
testcase_23 AC 44 ms
13,708 KB
testcase_24 AC 20 ms
8,400 KB
testcase_25 AC 71 ms
18,860 KB
testcase_26 AC 55 ms
14,736 KB
testcase_27 AC 153 ms
29,208 KB
testcase_28 AC 35 ms
11,400 KB
testcase_29 AC 123 ms
25,248 KB
testcase_30 AC 69 ms
17,196 KB
testcase_31 AC 130 ms
25,740 KB
testcase_32 AC 43 ms
12,988 KB
testcase_33 AC 227 ms
37,712 KB
testcase_34 AC 227 ms
37,492 KB
testcase_35 AC 235 ms
37,644 KB
testcase_36 AC 2 ms
6,940 KB
testcase_37 AC 2 ms
6,944 KB
testcase_38 AC 2 ms
6,944 KB
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 # 

// >>> TEMPLATES
#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using ld = long double;
using i32 = int32_t;
using i64 = int64_t;
using u32 = uint32_t;
using u64 = uint64_t;
#define int ll
#define rep(i, n) for (int i = 0; i < (int)(n); i++)
#define rep1(i, n) for (int i = 1; i <= (int)(n); i++)
#define repR(i, n) for (int i = (int)(n)-1; i >= 0; i--)
#define rep1R(i, n) for (int i = (int)(n); i >= 1; i--)
#define loop(i, a, B) for (int i = a; i B; i++)
#define loopR(i, a, B) for (int i = a; i B; i--)
#define all(x) begin(x), end(x)
#define allR(x) rbegin(x), rend(x)
#define rng(x, l, r) begin(x) + (l), begin(x) + (r)
#define pb push_back
#define eb emplace_back
#define fst first
#define snd second
template <class A, class B> constexpr auto mp(A &&a, B &&b) { return make_pair(forward<A>(a), forward<B>(b)); }
template <class... T> constexpr auto mt(T&&... x) { return make_tuple(forward<T>(x)...); }
template <class Int> auto constexpr inf_ = numeric_limits<Int>::max()/2-1;
auto constexpr INF32 = inf_<int32_t>;
auto constexpr INF64 = inf_<int64_t>;
auto constexpr INF   = inf_<int>;
#ifdef LOCAL
#include "debug.hpp"
#else
#define dump(...) (void)(0)
#define say(x) (void)(0)
#define debug if (0)
#endif
template <class T, class Comp> struct pque : priority_queue<T, vector<T>, Comp> { vector<T> &data() { return this->c; } void clear() { this->c.clear(); } };
template <class T> using pque_max = pque<T, less<T>>;
template <class T> using pque_min = pque<T, greater<T>>;
template <class T, class = typename T::iterator, enable_if_t<!is_same<T, string>::value, int> = 0>
ostream& operator<<(ostream& os, T const& a) { bool f = true; for (auto const& x : a) os << (f ? "" : " ") << x, f = false; return os; }
template <class T, size_t N, enable_if_t<!is_same<T, char>::value, int> = 0>
ostream& operator<<(ostream& os, const T (&a)[N]) { bool f = true; for (auto const& x : a) os << (f ? "" : " ") << x, f = false; return os; }
template <class T, class = decltype(begin(declval<T&>())), class = typename enable_if<!is_same<T, string>::value>::type>
istream& operator>>(istream& is, T &a) { for (auto& x : a) is >> x; return is; }
template <class T, class S> ostream& operator<<(ostream& os, pair<T, S> const& p) { return os << p.first << " " << p.second; }
template <class T, class S> istream& operator>>(istream& is, pair<T, S>& p) { return is >> p.first >> p.second; }
struct IOSetup { IOSetup() { cin.tie(nullptr); ios::sync_with_stdio(false); cout << fixed << setprecision(15); } } iosetup;
template <class F> struct FixPoint : private F {
    constexpr FixPoint(F&& f) : F(forward<F>(f)) {}
    template <class... T> constexpr auto operator()(T&&... x) const { return F::operator()(*this, forward<T>(x)...); }
};
struct MakeFixPoint { template <class F> constexpr auto operator|(F&& f) const { return FixPoint<F>(forward<F>(f)); } };
#define MFP MakeFixPoint()|
#define def(name, ...) auto name = MFP [&](auto &&name, __VA_ARGS__)
template <class T, size_t d> struct vec_impl {
    using type = vector<typename vec_impl<T, d-1>::type>;
    template <class... U> static type make_v(size_t n, U&&... x) { return type(n, vec_impl<T, d-1>::make_v(forward<U>(x)...)); }
};
template <class T> struct vec_impl<T, 0> { using type = T; static type make_v(T const& x = {}) { return x; } };
template <class T, size_t d = 1> using vec = typename vec_impl<T, d>::type;
template <class T, size_t d = 1, class... Args> auto make_v(Args&&... args) { return vec_impl<T, d>::make_v(forward<Args>(args)...); }
template <class T> void quit(T const& x) { cout << x << endl; exit(0); }
template <class T, class U> constexpr bool chmin(T& x, U const& y) { if (x > (T)y) { x = (T)y; return true; } return false; }
template <class T, class U> constexpr bool chmax(T& x, U const& y) { if (x < (T)y) { x = (T)y; return true; } return false; }
template <class It> constexpr auto sumof(It b, It e) { return accumulate(b, e, typename iterator_traits<It>::value_type{}); }
template <class T> int sz(T const& x) { return x.size(); }
template <class C, class T> int lbd(C const& v, T const& x) { return lower_bound(begin(v), end(v), x)-begin(v); }
template <class C, class T> int ubd(C const& v, T const& x) { return upper_bound(begin(v), end(v), x)-begin(v); }
constexpr int64_t mod(int64_t x, int64_t m) { assert(m > 0); return (x %= m) < 0 ? x+m : x; }
constexpr int64_t div_floor(int64_t x, int64_t y) { assert(y != 0); return x/y - ((x^y) < 0 and x%y); }
constexpr int64_t div_ceil(int64_t x, int64_t y) { assert(y != 0); return x/y + ((x^y) > 0 and x%y); }
constexpr int dx[] = { 1, 0, -1, 0, 1, -1, -1, 1 };
constexpr int dy[] = { 0, 1, 0, -1, 1, 1, -1, -1 };
constexpr int popcnt(ll x) { return __builtin_popcountll(x); }
mt19937_64 seed_{random_device{}()};
template <class Int> Int rand(Int a, Int b) { return uniform_int_distribution<Int>(a, b)(seed_); }
i64 irand(i64 a, i64 b) { return rand<i64>(a, b); } // [a, b]
u64 urand(u64 a, u64 b) { return rand<u64>(a, b); } //
template <class It> void shuffle(It l, It r) { shuffle(l, r, seed_); }
template <class T> vector<T> &operator--(vector<T> &v) { for (T &x : v) --x; return v; }
template <class T> vector<T> &operator++(vector<T> &v) { for (T &x : v) ++x; return v; }
// <<<
// >>> bfs
#ifndef EDGE_INFO
#define EDGE_INFO
constexpr int dest(int v) { return v; }
template <class E, class = decltype(declval<E>().to)>
constexpr int dest(E const& e) { return e.to; }
constexpr int cost(int) { return 1; }
template <class E, class = decltype(declval<E>().cost)>
constexpr auto cost(E const& e) { return e.cost; }
template <class E> using cost_t = decltype(cost(declval<E>()));
#endif
template <class E>
vector<int> bfs(vector<vector<E>> const& g, int s, int inf) {
    vector<int> d(g.size(), inf);
    queue<int> q;
    d[s] = 0;
    q.push(s);
    while (q.size()) {
        int x = q.front(); q.pop();
        for (auto const& e : g[x]) {
            const int y = dest(e);
            if (chmin(d[y], d[x]+1)) q.push(y);
        }
    }
    return d;
}
// <<<
// >>> Dinic
template <class Flow>
struct Dinic {
    static constexpr Flow INF = numeric_limits<Flow>::max();
    static constexpr Flow EPS = 1e-10; //

    struct Edge {
        int32_t to, rev, id;
        Flow cap;
        Edge(int to, int rev, int id, Flow cap)
            : to(to), rev(rev), id(id), cap(cap) {}
    };
    vector<vector<Edge>> g;
    vector<pair<int32_t, int32_t>> es;
    vector<int32_t> level, iter;
    int V, E, s, t;

    Dinic(int V = 0) : g(V), V(V), E(0), s(-1), t(-1) {}
    void add_edge(int from, int to, Flow cap) {
        assert(0 <= from); assert(from < V);
        assert(0 <= to); assert(to < V);
        assert(cap >= 0);
        es.emplace_back(from, g[from].size());
        g[from].emplace_back(to, g[to].size(), E, cap);
        g[to].emplace_back(from, g[from].size()-1, E, 0);
        E++;
    }

    struct edge_t {
        int32_t from, to;
        Flow flow, cap;
    };
    Edge& internal_edge(int id) {
        assert(0 <= id); assert(id < (int)es.size());
        int from, idx; tie(from, idx) = es[id];
        return g[from][idx];
    }
    edge_t edge(int id) const {
        assert(0 <= id); assert(id < (int)es.size());
        int32_t from, idx; tie(from, idx) = es[id];
        auto const& e = g[from][idx];
        auto const& r = g[e.to][e.rev];
        return { from, e.to, r.cap, e.cap+r.cap };
    }
    vector<edge_t> edges() const {
        vector<edge_t> ret(E);
        rep (id, E) ret[id] = edge(id);
        return ret;
    }

    bool bfs() {
        level.assign(V, -1);
        queue<int> q;
        level[s] = 0;
        q.push(s);
        while (q.size() && level[t] < 0) {
            int x = q.front(); q.pop();
            for (auto const& e : g[x]) {
                if (e.cap > EPS && level[e.to] < 0) {
                    level[e.to] = level[x] + 1;
                    q.push(e.to);
                }
            }
        }
        return level[t] >= 0;
    }

    Flow dfs(int x, Flow f = INF) {
        if (x == t) return f;
        Flow res = 0;
        for (auto &i = iter[x]; i < int(g[x].size()); ++i) {
            auto &e = g[x][i];
            if (e.cap > EPS && level[x] < level[e.to]) {
                Flow d = dfs(e.to, min(f, e.cap));
                e.cap -= d;
                g[e.to][e.rev].cap += d;
                res += d;
                f -= d;
                if (f == 0) break;
            }
        }
        return res;
    }

    Flow max_flow(int s, int t) {
        assert(0 <= s); assert(s < V);
        assert(0 <= t); assert(t < V);
        this-> s = s; this->t = t;
        Flow flow = 0;
        while (bfs()) {
            iter.assign(V, 0);
            for (Flow f = 0; (f = dfs(s)); flow += f) {}
        }
        return flow;
    }

#ifdef LOCAL
    friend string to_s(Dinic d) {
        string ret = "\n";
        ret += "V = " + to_s(d.V) + ", E = " + to_s(d.E) + "\n";
        ret += "s = " + to_s(d.s) + ", t = " + to_s(d.t) + "\n";
        for (auto const& p : d.es) {
            auto const& e = d.g[p.first][p.second];
            auto const& r = d.g[e.to][e.rev];
            ret += to_s(e.id) + " : ";
            ret += to_s(p.first) + "->" + to_s(e.to) + " : ";
            ret += to_s(r.cap) + "/" + to_s(e.cap+r.cap) + "\n";
        }
        return ret;
    }
#endif

};
// <<<

int32_t main() {
    int n; cin >> n;
    vector<vector<int>> g(n);
    rep (i, n-1) {
        int x, y; cin >> x >> y; --x, --y;
        g[x].eb(y);
        g[y].eb(x);
    }

    auto dep = bfs(g, 0, INF);
    Dinic<int> dinic(n+2);
    const int S = n, T = n+1;
    rep (x, n) {
        if (dep[x] % 2 == 0) {
            dinic.add_edge(S, x, 1);
        } else {
            dinic.add_edge(x, T, 1);
        }
    }
    rep (x, n) for (int y : g[x]) {
        if (dep[x] % 2 == 0) {
            dinic.add_edge(x, y, 1);
        } else {
            dinic.add_edge(y, x, 1);
        }
    }

    cout << dinic.max_flow(S, T) << '\n';


}
0