結果

問題 No.898 tri-βutree
コンテスト
ユーザー alexara1123
提出日時 2019-11-13 12:18:28
言語 C++14
(gcc 13.3.0 + boost 1.87.0)
結果
AC  
実行時間 369 ms / 4,000 ms
コード長 4,289 bytes
コンパイル時間 1,370 ms
コンパイル使用メモリ 110,008 KB
実行使用メモリ 20,536 KB
最終ジャッジ日時 2024-11-08 23:09:27
合計ジャッジ時間 9,436 ms
ジャッジサーバーID
（参考情報） 		judge5 / judge1
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 * 1
other AC * 21
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 # 

#include <cstdio>
#include <cstdlib>
#include <algorithm>
#include <vector>
#include <string>
#include <cstring>
#include <queue>
#include <set>
#include <unordered_set>
#include <unordered_map>
#include <map>
#include <numeric>
#include <functional>
#include <cmath>
#include <cassert>
#include <string>
#include <iostream>

using namespace std;
typedef long long ll;
typedef pair<int, int> P;
typedef pair<ll, ll> PL;
const ll MOD = 1000000007;
const int mod = 1000000007;
ll INF = 1LL << 60;

template <typename T>
istream &operator>>(istream &is, vector<T> &vec)
{
   for (auto &v : vec)
      is >> v;
   return is;
}
template <typename T>
ostream &operator<<(ostream &os, const vector<T> &vec)
{
   os << "[";
   for (auto v : vec)
      os << v << ",";
   os << "]";
   return os;
}
template <typename T>
ostream &operator<<(ostream &os, const deque<T> &vec)
{
   os << "deq[";
   for (auto v : vec)
      os << v << ",";
   os << "]";
   return os;
}
template <typename T>
ostream &operator<<(ostream &os, const set<T> &vec)
{
   os << "{";
   for (auto v : vec)
      os << v << ",";
   os << "}";
   return os;
}
template <typename T>
ostream &operator<<(ostream &os, const unordered_set<T> &vec)
{
   os << "{";
   for (auto v : vec)
      os << v << ",";
   os << "}";
   return os;
}
template <typename T>
ostream &operator<<(ostream &os, const multiset<T> &vec)
{
   os << "{";
   for (auto v : vec)
      os << v << ",";
   os << "}";
   return os;
}
template <typename T>
ostream &operator<<(ostream &os, const unordered_multiset<T> &vec)
{
   os << "{";
   for (auto v : vec)
      os << v << ",";
   os << "}";
   return os;
}
template <typename T1, typename T2>
ostream &operator<<(ostream &os, const pair<T1, T2> &pa)
{
   os << "(" << pa.first << "," << pa.second << ")";
   return os;
}
template <typename TK, typename TV>
ostream &operator<<(ostream &os, const map<TK, TV> &mp)
{
   os << "{";
   for (auto v : mp)
      os << v.first << "=>" << v.second << ",";
   os << "}";
   return os;
}
template <typename TK, typename TV>
ostream &operator<<(ostream &os, const unordered_map<TK, TV> &mp)
{
   os << "{";
   for (auto v : mp)
      os << v.first << "=>" << v.second << ",";
   os << "}";
   return os;
};
#define dbg(x) cerr << #x << " = " << (x) << " (L" << __LINE__ << ") " << __FILE__ << endl;
template <typename A, size_t N, typename T>
void Fill(A (&array)[N], const T &val)
{
   fill((T *)array, (T *)(array + N), val);
}

struct LCA
{
   int n, h;
   vector<vector<int>> par;
   vector<vector<pair<int, int>>> v;
   vector<ll> depth, dis;
   LCA(int sz) : n(sz), v(n), depth(n), dis(n)
   {
      h = 1;
      while ((1 << h) < n)
         h++;
      par.assign(h, vector<int>(n, -1));
   }

   void add_edge(int x, int y, int z)
   {
      v[x].push_back({y, z});
      v[y].push_back({x, z});
   }

   void dfs(int x, int p, int d, ll di)
   {
      par[0][x] = p;
      depth[x] = d;
      dis[x] = di;
      for (auto to : v[x])
         if (to.first != p)
            dfs(to.first, x, d + 1, di + to.second);
   }

   void build()
   {
      dfs(0, -1, 0, 0);
     for(int i=0; i < h-1; i++)
      {
         for(int j=0; j < n; j++)
         {
            if (par[i][j] < 0)
               par[i + 1][j] = -1;
            else
               par[i + 1][j] = par[i][par[i][j]];
         }
      }
   }

   int lca(int u, int v)
   {
      if (depth[u] > depth[v])
         swap(u, v);
      for(int i=0; i < h; i++) if ((depth[v] - depth[u]) >> i & 1) v = par[i][v];
      if (u == v)
         return u;
      for (int i = h - 1; i >= 0; i--)
      {
         if (par[i][u] != par[i][v])
         {
            u = par[i][u];
            v = par[i][v];
         }
      }
      return par[0][u];
   }

   ll dist(int u, int v)
   {
      return dis[u] + dis[v] - 2 * dis[lca(u, v)];
   }
};

int solve()
{
   ll n;
   cin >> n;
   LCA lca(n);
   for(int i=0; i < n-1; i++){
      ll u, v, w;
      cin >> u >> v >> w;
      lca.add_edge(u, v, w);
   }
   lca.build();
   ll q;
   cin >> q;
   while (q--)
   {
      ll a,b,c;
      cin >> a >> b >> c;
      cout << (lca.dist(a,b) + lca.dist(b,c) + lca.dist(c,a))/2 << endl;
   }
   
   return 0;
}

int main()
{
   //cout.precision(10)
   ios::sync_with_stdio(false);
   cin.tie(0);

   solve();
}
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