#387088 (C++14) No.898 tri-βutree

• 問題: No.898 tri-βutree
• ユーザー: peroon
• 提出日時: 2019-10-05 03:58:26
• 言語: C++14 (gcc 13.3.0 + boost 1.87.0)
• 結果: AC
• 実行時間: 680 ms / 4,000 ms
• コード長: 7,314 bytes
• コンパイル時間: 2,525 ms
• コンパイル使用メモリ: 192,384 KB
• 実行使用メモリ: 43,904 KB
• 最終ジャッジ日時: 2024-11-08 22:47:50
• 合計ジャッジ時間: 13,537 ms
• ジャッジサーバーID （参考情報）: judge1 / judge4

ファイルパターン	結果
sample	AC * 1
other	AC * 21

ソースコード

#include<bits/stdc++.h>
using namespace std;
using ll = long long;
using VI = vector<ll>;
using VV = vector<VI>;
using VS = vector<string>;

// tourist set
template <typename A, typename B>
string to_string(pair<A, B> p);

template <typename A, typename B, typename C>
string to_string(tuple<A, B, C> p);

template <typename A, typename B, typename C, typename D>
string to_string(tuple<A, B, C, D> p);

string to_string(const string& s) {
  return '"' + s + '"';
}

string to_string(const char* s) {
  return to_string((string) s);
}

string to_string(bool b) {
  return (b ? "true" : "false");
}

string to_string(vector<bool> v) {
  bool first = true;
  string res = "{";
  for (int i = 0; i < static_cast<int>(v.size()); i++) {
    if (!first) {
      res += ", ";
    }
    first = false;
    res += to_string(v[i]);
  }
  res += "}";
  return res;
}

template <size_t N>
string to_string(bitset<N> v) {
  string res = "";
  for (size_t i = 0; i < N; i++) {
    res += static_cast<char>('0' + v[i]);
  }
  return res;
}

template <typename A>
string to_string(A v) {
  bool first = true;
  string res = "{";
  for (const auto &x : v) {
    if (!first) {
      res += ", ";
    }
    first = false;
    res += to_string(x);
  }
  res += "}";
  return res;
}

template <typename A, typename B>
string to_string(pair<A, B> p) {
  return "(" + to_string(p.first) + ", " + to_string(p.second) + ")";
}

template <typename A, typename B, typename C>
string to_string(tuple<A, B, C> p) {
  return "(" + to_string(get<0>(p)) + ", " + to_string(get<1>(p)) + ", " + to_string(get<2>(p)) + ")";
}

template <typename A, typename B, typename C, typename D>
string to_string(tuple<A, B, C, D> p) {
  return "(" + to_string(get<0>(p)) + ", " + to_string(get<1>(p)) + ", " + to_string(get<2>(p)) + ", " + to_string(get<3>(p)) + ")";
}

void debug_out() { cerr << endl; }

template <typename Head, typename... Tail>
void debug_out(Head H, Tail... T) {
  cerr << " " << to_string(H);
  debug_out(T...);
}

#ifdef LOCAL
#define debug(...) cerr << "[" << #__VA_ARGS__ << "]:", debug_out(__VA_ARGS__)
#else
#define debug(...) 42
#endif
// tourist set end

template<class T>bool chmax(T &a, const T &b) { if (a<b) { a=b; return 1; } return 0; }
template<class T>bool chmin(T &a, const T &b) { if (b<a) { a=b; return 1; } return 0; }

#define FOR(i,a,b) for(ll i=(a);i<(b);++i)
#define rep(i,b) FOR(i, 0, b)
#define ALL(v) (v).begin(), (v).end()
#define p(s) cout<<(s)<<endl
#define p2(s, t) cout << (s) << " " << (t) << endl
#define br() p("")
#define pn(s) cout << (#s) << " " << (s) << endl
#define p_yes() p("YES")
#define p_no() p("NO")
#define SZ(x) ((int)(x).size())

void no(){p_no(); exit(0);}
void yes(){p_yes(); exit(0);}

const ll mod = 1e9 + 7;
const ll inf = 1e18;

struct Edge{
    ll to;
    ll cost;
    Edge(ll to, ll cost): to(to), cost(cost) {}
    Edge(){
        to = 0;
        cost = 0;
    }
};

struct Node{
    ll distance;
    ll index;
    Node(ll d, ll i){
        distance = d;
        index = i;
    }
    Node(){}

    bool operator<(const Node &another) const
    {
        return distance < another.distance;
    }
    bool operator>(const Node &another) const
    {
        return distance > another.distance;
    }
};

struct Dijkstra{
    vector<ll> d;
    vector<vector<Edge> > graph;
    vector<bool> done;

    // ノード数を入れる
    void initialize(ll size){
        d.resize(size);
        done.resize(size);
        graph.resize(size);
        reset();
    }

    void reset(){
        ll N = graph.size();
        FOR(i, 0, N){
            d[i] = inf;
            done[i] = false;
        }
    }
    
    ll distance(int i){
        if(d.size()<=i) return -1;
        return d[i];
    }

    void print_graph(){
        FOR(i, 0, graph.size()){
            cout << i << " -> ";

            for(auto edge : graph[i]){
                cout << edge.to << " ";
            }
            cout << endl;
        }
        p("distance");
        FOR(i, 0, graph.size()){
            ll d = distance(i);
            cout << i << " " << d << endl;
        }
    }

    void register_edge(ll a, ll b, ll cost){
        auto edge = Edge(b, cost);
        graph[a].push_back(edge);
    }

    void calc_shortest_path(ll from=0){
        priority_queue<Node, vector<Node>, greater<Node> > que;
        auto node = Node();
        // 始点
        node.index = from;
        node.distance = 0;
        que.push(node);

        while(!que.empty()){
            // 1番distanceが小さいノード
            Node n = que.top();
            que.pop();

            if(done[n.index]){
                continue;
            }
            
            done[n.index] = true;
            d[n.index] = n.distance;

            auto edge_list = graph[n.index];
            for(auto edge : edge_list){   
                // 短くなるノードがあれば
                if(!done[edge.to] && n.distance + edge.cost < d[edge.to]){
                    ll shorter_distance = n.distance + edge.cost;
                    que.push(Node(shorter_distance, edge.to));
                }
            }
        }
    }
};

void vprint(vector<ll> A){
    ll L = A.size();
    FOR(i, 0, L){
        if(i) cout << ' ';
        cout << A[i];
    }
    cout << endl;
}

// LCA set
VV G;
const int N_MAX = 100010;
const int MAX_LOG_V = 20;
ll depth[N_MAX] = {};
ll parent[MAX_LOG_V][N_MAX] = {};
void dfs(ll index, ll prev, ll _depth){
    depth[index] = _depth;
    parent[0][index] = prev;
 
    auto list = G[index];
    for(ll to : list){
        if(to==prev){
            continue;
        }
        dfs(to, index, _depth+1);
    }
    return;
}
 
ll LCA(ll a, ll b){
    if(a==b){
        return a;
    }
 
    // aよりbが深い（または同じ）と仮定する
    if(depth[a] > depth[b]){
        swap(a, b);
    }
    
    // bを根側に辿っていく
    ll diff_depth = depth[b] - depth[a];
    FOR(k, 0, MAX_LOG_V){
        if(diff_depth >> k & 1){
            b = parent[k][b];
        }
    }
 
    // aとbの深さが揃った
    if(a==b){
        return a;
    }
 
    // 大きい歩幅で共通親までジャンプ
    for(int k=MAX_LOG_V-1; k>=0; k--){
        if(parent[k][a] != parent[k][b]){
            a = parent[k][a];
            b = parent[k][b];
        }
    }
 
    // 1つ上がLCA
    return parent[0][a];
}
void prepare_LCA(ll N){
    // dfs(1, -1, 0);
    dfs(0, -1, 0);
 
    // ダブリングで親 2^k
    FOR(k, 1, MAX_LOG_V){
      FOR(i, 1, N+1){
        ll p = parent[k-1][i];
        if(p==-1) continue;
        parent[k][i] = parent[k-1][p];
      }
    }
}

// LCA set end

Dijkstra dij;

ll f(ll u, ll v){
  ll p = LCA(u, v);
  ll d = dij.distance(u) + dij.distance(v) - 2*dij.distance(p);
  return d;
}

int main(){
    cin.tie(0);
    ios::sync_with_stdio(false);

    // input
    ll N;
    cin >> N;

    G.resize(N);

    dij.initialize(N);
    rep(i, N-1){
      ll u, v, w;
      cin >> u >> v >> w;
      dij.register_edge(u, v, w);
      dij.register_edge(v, u, w);
      G[u].push_back(v);
      G[v].push_back(u);
    }
    dij.calc_shortest_path(0);

    prepare_LCA(N);

    ll Q;
    cin >> Q;
    while(Q--){
      ll x, y, z;
      cin >> x >> y >> z;
      ll ans = f(x, y) + f(y, z) + f(z, x);
      p(ans/2);
    }
    
    return 0;
}