結果
| 問題 |
No.2677 Minmax Independent Set
|
| コンテスト | |
| ユーザー |
 横山緑
|
| 提出日時 | 2025-03-07 18:43:56 |
| 言語 | C++23 (gcc 13.3.0 + boost 1.87.0) |
| 結果 |
AC
|
| 実行時間 | 237 ms / 2,000 ms |
| コード長 | 8,639 bytes |
| コンパイル時間 | 4,247 ms |
| コンパイル使用メモリ | 289,468 KB |
| 実行使用メモリ | 80,176 KB |
| 最終ジャッジ日時 | 2025-03-07 18:44:10 |
| 合計ジャッジ時間 | 12,854 ms |
|
ジャッジサーバーID （参考情報） |
judge5 / judge2 |
（要ログイン）
| ファイルパターン | 結果 |
|---|---|
| sample | AC * 3 |
| other | AC * 61 |
ソースコード
#line 2 "template.hpp"
// #pragma GCC target("avx2")
// #pragma GCC optimize("O3")
// #pragma GCC optimize("unroll-loops")
#include <bits/stdc++.h>
using namespace std;
// https://xn--kst.jp/blog/2019/08/29/cpp-comp/
// debug methods
// usage: debug(x,y);
// vector 出力できるように修正
template <typename T>
ostream& debug_print(ostream& os, const vector<T>& v) {
os << "[";
for (size_t i = 0; i < v.size(); ++i) {
os << v[i];
if (i < v.size() - 1) os << ", ";
}
os << "]";
return os;
}
template <typename T>
ostream& debug_print(ostream& os, const T& var) {
os << var;
return os;
}
#define CHOOSE(a) CHOOSE2 a
#define CHOOSE2(a0, a1, a2, a3, a4, x, ...) x
#define debug_1(x1) { cout << #x1 << ": "; debug_print(cout, x1) << endl; }
#define debug_2(x1, x2) { cout << #x1 << ": "; debug_print(cout, x1) << ", " << #x2 << ": "; debug_print(cout, x2) << endl; }
#define debug_3(x1, x2, x3) { cout << #x1 << ": "; debug_print(cout, x1) << ", " << #x2 << ": "; debug_print(cout, x2) << ", " << #x3 << ": "; debug_print(cout, x3) << endl; }
#define debug_4(x1, x2, x3, x4) { cout << #x1 << ": "; debug_print(cout, x1) << ", " << #x2 << ": "; debug_print(cout, x2) << ", " << #x3 << ": "; debug_print(cout, x3) << ", " << #x4 << ": "; debug_print(cout, x4) << endl; }
#define debug_5(x1, x2, x3, x4, x5) { cout << #x1 << ": "; debug_print(cout, x1) << ", " << #x2 << ": "; debug_print(cout, x2) << ", " << #x3 << ": "; debug_print(cout, x3) << ", " << #x4 << ": "; debug_print(cout, x4) << ", " << #x5 << ": "; debug_print(cout, x5) << endl; }
#ifdef LOCAL
#define debug(...) CHOOSE((__VA_ARGS__, debug_5, debug_4, debug_3, debug_2, debug_1, ~))(__VA_ARGS__)
#else
#define debug(...)
#endif
using ll = long long;
using vl = vector<ll>;
using vll = vector<vl>;
using P = pair<ll, ll>;
#define all(v) v.begin(), v.end()
template <typename T> inline bool chmax(T &a, T b) {
return ((a < b) ? (a = b, true) : (false));
}
template <typename T> inline bool chmin(T &a, T b) {
return ((a > b) ? (a = b, true) : (false));
}
#define rep1(i, n) for(ll i = 1; i <= ((ll)n); ++i)
// https://trap.jp/post/1224/
template <class... T> constexpr auto min(T... a) {
return min(initializer_list<common_type_t<T...>>{a...});
}
template <class... T> constexpr auto max(T... a) {
return max(initializer_list<common_type_t<T...>>{a...});
}
template <class... T> void input(T &...a) { (cin >> ... >> a); }
template <class T> void input(vector<T> &a) {
for(T &x : a)
cin >> x;
}
void print() { cout << '\n'; }
template <class T, class... Ts> void print(const T &a, const Ts &...b) {
cout << a;
(cout << ... << (cout << ' ', b));
cout << '\n';
}
void print(const string &s) {
cout << s << '\n';
}
template <class Container, typename = void>
struct is_container : std::false_type {};
template <class Container>
struct is_container<Container, std::void_t<decltype(std::declval<Container>().begin()), decltype(std::declval<Container>().end())>> : std::true_type {};
template <class Container>
typename enable_if<is_container<Container>::value>::type print(const Container& x) {
if (!x.empty()) {
auto it = x.begin();
for (; it != prev(x.end()); ++it) {
cout << *it << " ";
}
cout << *it << "\n"; // 最後の要素を出力して改行
}
}
#define INT(...) \
int __VA_ARGS__; \
input(__VA_ARGS__)
#define LL(...) \
long long __VA_ARGS__; \
input(__VA_ARGS__)
#define STR(...) \
string __VA_ARGS__; \
input(__VA_ARGS__)
#define REP1(a) for(ll i = 0; i < a; i++)
#define REP2(i, a) for(ll i = 0; i < a; i++)
#define REP3(i, a, b) for(ll i = a; i < b; i++)
#define REP4(i, a, b, c) for(ll i = a; i < b; i += c)
#define overload4(a, b, c, d, e, ...) e
#define rep(...) overload4(__VA_ARGS__, REP4, REP3, REP2, REP1)(__VA_ARGS__)
ll inf = 3e18;
vl dx = {1, -1, 0, 0};
vl dy = {0, 0, 1, -1};
#line 3 "graph/graph-template.hpp"
// https://ei1333.github.io/library/graph/graph-template.hpp
template <class T = ll> struct Edge {
int from, to;
T cost;
int idx;
Edge() = default;
Edge(int from, int to, T cost = 1, int idx = -1)
: from(from), to(to), cost(cost), idx(idx) {}
Edge &operator=(const int &x) {
to = x;
return *this;
}
operator int() const { return to; }
};
template <class T = ll> struct Graph {
using cost_type = T;
vector<vector<Edge<T>>> g;
int es; // edge_size
Graph(int n) : g(n), es(0) {};
int size() const { return ssize(g); }
void add_directed_edge(int from, int to, T cost = 1) {
g[from].emplace_back(from, to, cost, es++);
}
void add_edge(int from, int to, T cost = 1) {
g[from].emplace_back(from, to, cost, es);
g[to].emplace_back(to, from, cost, es++);
}
vector<Edge<T>> &operator[](const int &k) { return g[k]; }
const vector<Edge<T>> &operator[](const int &k) const { return g[k]; }
void read(int m, int padding = -1, bool weighted = false,
bool directed = false) {
rep(i, m) {
int a, b;
T c(1);
cin >> a >> b;
a += padding;
b += padding;
if(weighted)
cin >> c;
if(directed)
add_directed_edge(a, b, c);
else
add_edge(a, b, c);
}
}
};
#line 2 "/home/y_midori/cp/test/a.cpp"
// #include "math/factorial.hpp"
#line 3 "tree/rerooting.hpp"
// https://atcoder.jp/contests/abc222/editorial/2749
// https://nyaannyaan.github.io/library/tree/rerooting.hpp
// TreeType : Graph<Cost>
// MergeFunc : Data(Data,Data)
// ApplyFunc : Data(Data,int from,int to,Cost)
/*
using Data = ;
using Cost = ;
Graph<Cost> g;
Data leaf = ;
auto merge = [](Data a, Data b) {};
auto apply = [](Data data, int from, int to, Cost cost) {};
Rerooting<Data, decltype(g), decltype(merge), decltype(apply)> dp(
g, merge, apply, leaf);
*/
template <class Data, class TreeType, class MergeFunc, class ApplyFunc>
struct Rerooting {
const TreeType &g;
const MergeFunc merge;
const ApplyFunc apply;
const Data leaf;
vector<Data> dp, memo;
Rerooting(const TreeType &g, MergeFunc merge, ApplyFunc apply, Data leaf)
: g(g), merge(merge), apply(apply), leaf(leaf), dp(g.size(), leaf),
memo(g.size(), leaf) {
dfs1(0, -1);
dfs2(0, -1, leaf);
}
const Data &operator[](int i) const { return dp[i]; }
void dfs1(int cur, int p) {
for(auto &d : g[cur]) {
if(d.to == p)
continue;
dfs1(d.to, cur);
memo[cur] = merge(memo[cur], apply(memo[d.to], d.to, cur, d.cost));
}
}
void dfs2(int cur, int p, const Data &val) {
vector<Data> ds{val};
for(auto &d : g[cur]) {
if(d.to == p)
continue;
ds.emplace_back(apply(memo[d.to], d.to, cur, d.cost));
}
vector<Data> left(ds.size() + 1, leaf), right(ds.size() + 1, leaf);
for(int i = 0; i + 1 < left.size(); i++)
left[i + 1] = merge(left[i], ds[i]);
for(int i = ssize(right) - 2; 0 < i; i--)
right[i] = merge(right[i + 1], ds[i]);
dp[cur] = left.back();
int idx = 1;
for(auto &d : g[cur]) {
if(d.to == p)
continue;
Data tmp = merge(left[idx], right[idx + 1]);
tmp = apply(tmp, cur, d.to, d.cost);
dfs2(d.to, cur, tmp);
idx++;
}
}
};
#line 5 "/home/y_midori/cp/test/a.cpp"
struct Data {
int w, b;
};
void solve() {
INT(n);
Graph<bool> g(n);
g.read(n - 1);
auto merge = [](Data a, Data b) { return Data(a.w + b.w, a.b + b.b); };
auto apply = [](Data data, int from, int to, bool) {
Data res;
res.b = data.w;
res.w = max(data.w, 1 + data.b);
return res;
};
Rerooting<Data, decltype(g), decltype(merge), decltype(apply)> dp(
g, merge, apply, Data(0, 0));
int ans = n;
rep(i, n) {
chmin(ans, 1 + dp[i].b);
}
print(ans);
}
int main() {
ios::sync_with_stdio(false);
std::cin.tie(nullptr);
ll t = 1;
// cin >> t;
rep(_, t) {
solve();
}
}