test/yosupo/Tree/Tree-Diameter.test.cpp

• View this file on GitHub
• Last update: 2023-11-12 01:15:26+09:00
• Problem: https://judge.yosupo.jp/problem/tree_diameter

Depends on

• Diameter(木の直径) (graph/diameter.hpp)
• Graph Template (graph/template.hpp)
• others/fastIO.hpp
• template/template.hpp

Code

#define PROBLEM "https://judge.yosupo.jp/problem/tree_diameter"

#include "../../../template/template.hpp"

#include "../../../graph/diameter.hpp"
#include "../../../others/fastIO.hpp"

int main(){
  int n;
  cin >> n;
  Graph<ll> root(n);
  rep(i, n - 1){
    int a,b,c;
    cin >> a >> b >> c;
    root[a].push_back({ a, b, c });
    root[b].push_back({ b, a, c });
  }
  const auto res = diameter(root);
  const int m = res.second.size();
  cout << res.first << ' ' << m << '\n';
  rep(i, m) cout << res.second[i] << " \n"[i == m - 1];
}

#line 1 "test/yosupo/Tree/Tree-Diameter.test.cpp"
#define PROBLEM "https://judge.yosupo.jp/problem/tree_diameter"

#line 1 "template/template.hpp"
#include <iostream>
#include <cmath>
#include <string>
#include <vector>
#include <algorithm>
#include <tuple>
#include <cstdint>
#include <cstdio>
#include <map>
#include <queue>
#include <set>
#include <stack>
#include <deque>
#include <bitset>
#include <cctype>
#include <climits>
#include <functional>
#include <cassert>
#include <numeric>
#include <cstring>
#define rep(i, n) for(int i = 0; i < (n); i++)
#define per(i, n) for(int i = (n) - 1; i >= 0; i--)
using ll = long long;
#define vi vector<int>
#define vvi vector<vi>
#define vl vector<ll>
#define pii pair<int, int>
#define pll pair<ll, ll>
#define all(a) (a).begin(), (a).end()
#define rall(a) (a).rbegin(), (a).rend()
constexpr int mod = 1000000007;
using namespace std;
template<class T, class U>
bool chmax(T &a, const U &b){ return a < b ? (a = b, 1) : 0; }
template<class T, class U>
bool chmin(T &a, const U &b){ return a > b ? (a = b, 1) : 0; }
#line 4 "test/yosupo/Tree/Tree-Diameter.test.cpp"

#line 2 "graph/template.hpp"

/**
 * @brief Graph Template
*/
template <class T>
struct Edge {
  int from,to;
  T cost;
  int idx;
  Edge(){};
  Edge(int f, int t, T c=1, int i=-1) : from(f), to(t), cost(c), idx(i){}
  Edge(int t) : to(t), from(-1), cost(1), idx(-1){}
  operator int() const{ return to; }
  bool operator<(const Edge &e){ return cost < e.cost; }
};
template <class T>
struct Graph : vector<vector<Edge<T>>> {
  Graph(){}
  Graph(const int &n) : vector<vector<Edge<T>>>(n){}
  void add_edge(int a, int b, T c=1, int i=-1){
    (*this)[a].push_back({ a, b, c, i });
  }
};
using graph = Graph<int>;
#line 2 "graph/diameter.hpp"

template <class T>
pair<T, vector<int>> diameter(const Graph<T> &g){
  const int n = g.size();
  vector<T> dist(n);
  vector<int> prev(n, -1);
  function<void(int,int)> dfs = [&](int pos, int par){
    for(auto &x : g[pos]) if(x != par){
      dist[x] = dist[pos] + x.cost;
      prev[x] = pos;
      dfs(x, pos);
    }
  };
  dfs(0, -1);
  int pos = max_element(dist.begin(), dist.end()) - dist.begin();
  dist.assign(n, 0); prev.assign(n, -1);
  dfs(pos, -1);
  pos = max_element(dist.begin(), dist.end()) - dist.begin();
  const T tot = dist[pos];
  vector<int> res;
  for(int i = pos; i != -1; i = prev[i]) res.push_back(i);
  return { tot, res };
}
#line 1 "others/fastIO.hpp"
namespace FastIO {
struct PreCalc {
  char num[10000 * 4];
  constexpr PreCalc() : num(){
    for(int i = 0; i < 10000; i++){
      int t = i;
      for(int j = 3; j >= 0; j--){
        num[i*4 + j] = (t % 10) + '0';
        t /= 10;
      }
    }
  }
};
static constexpr PreCalc pr;
struct FastIO {
  template <class T>
  using enable_if_integer = enable_if_t<is_integral<T>::value || is_same<T, __int128_t>::value || is_same<T, __uint128_t>::value>;
  static constexpr int buf_size = 1 << 20;
  static constexpr int rem = 1 << 6;
  char in_buf[buf_size], *in_cur = in_buf + buf_size;
  char out_buf[buf_size], *out_cur = out_buf;
  FastIO(){ load(); }
  ~FastIO(){ flush(); }
  void load(){
    const int len = in_buf + buf_size - in_cur;
    memmove(in_buf, in_cur, len);
    in_cur = in_buf;
    fread(in_buf + len, 1, buf_size - len, stdin);
  }
  void flush(){
    fwrite(out_buf, 1, out_cur - out_buf, stdout);
    out_cur = out_buf;
  }
  void through(){
    if(in_cur - in_buf >= buf_size - rem) load();
    while(*in_cur <= ' ') in_cur++;
    assert(in_buf <= in_cur && in_cur < in_buf + buf_size);
  }
  #define gc() (*in_cur++)
  template <class T, enable_if_integer<T>* = nullptr>
  inline void read(T &x){
    through();
    bool neg = false;
    int c = gc();
    if(c == '-') neg = true, c = gc();
    x = c^'0'; c = gc();
    while(c >= '0' && c <= '9') x = x*10 + (c^'0'), c = gc();
    if(neg) x = -x;
  }
  inline void read(string &x){
    through();
    x.clear();
    while(true){
      char *p = in_cur;
      while(*p > ' ' && p - in_buf < buf_size - rem) p++;
      copy(in_cur, p, back_inserter(x));
      in_cur = p;
      if(*p <= ' ') break;
      load();
    }
  }
  inline void read(char &x){
    through();
    x = gc();
  }
  #undef gc
  #define pc(c) *out_cur++ = (c)
  template <class T, enable_if_integer<T>* = nullptr>
  inline void out(T x){
    static constexpr int tmp_size = sizeof(T)*5/2;
    static char tmp[tmp_size];
    if(out_cur - out_buf >= buf_size - rem) flush();
    if(!x){ pc('0'); return; }
    if(x < 0){ pc('-'); x = -x; }
    int idx = tmp_size;
    while(x >= 10000){
      idx -= 4;
      memcpy(tmp + idx, pr.num + (x % 10000)*4, 4);
      x /= 10000;
    }
    if(x < 100){
      if(x < 10){
        pc(x + '0');
      }else{
        pc(x/10 + '0');
        pc(x%10 + '0');
      }
    }else{
      if(x < 1000){
        memcpy(out_cur, pr.num + x*4 + 1, 3);
        out_cur += 3;
      }else{
        memcpy(out_cur, pr.num + x*4, 4);
        out_cur += 4;
      }
    }
    memcpy(out_cur, tmp + idx, tmp_size - idx);
    out_cur += tmp_size - idx;
  }
  inline void out(const string &s){
    flush();
    fwrite(s.c_str(), 1, s.size(), stdout);
  }
  inline void out(const char c){
    if(out_cur - out_buf >= buf_size - rem) flush();
    pc(c);
  }
  #undef pc
  template <class T>
  friend FastIO &operator>>(FastIO &io, T &x){
    io.read(x);
    return io;
  }
  template <class T>
  friend FastIO &operator<<(FastIO &io, const T &x){
    io.out(x);
    return io;
  }
};
FastIO io;
} // namespace FastIO

using FastIO::io;
#define cin io
#define cout io
#line 7 "test/yosupo/Tree/Tree-Diameter.test.cpp"

int main(){
  int n;
  cin >> n;
  Graph<ll> root(n);
  rep(i, n - 1){
    int a,b,c;
    cin >> a >> b >> c;
    root[a].push_back({ a, b, c });
    root[b].push_back({ b, a, c });
  }
  const auto res = diameter(root);
  const int m = res.second.size();
  cout << res.first << ' ' << m << '\n';
  rep(i, m) cout << res.second[i] << " \n"[i == m - 1];
}

Back to top page