結果

問題 No.1094 木登り / Climbing tree
ユーザー peroonperoon
提出日時 2020-07-07 15:25:57
言語 C++14
(gcc 12.3.0 + boost 1.83.0)
結果
AC  
実行時間 506 ms / 2,000 ms
コード長 8,269 bytes
コンパイル時間 3,149 ms
コンパイル使用メモリ 203,384 KB
実行使用メモリ 68,864 KB
最終ジャッジ日時 2024-11-08 06:58:27
合計ジャッジ時間 15,486 ms
ジャッジサーバーID
（参考情報） 		judge4 / judge3
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
5,248 KB
testcase_01 AC 476 ms
64,512 KB
testcase_02 AC 144 ms
68,864 KB
testcase_03 AC 51 ms
6,528 KB
testcase_04 AC 127 ms
29,952 KB
testcase_05 AC 259 ms
56,576 KB
testcase_06 AC 174 ms
22,400 KB
testcase_07 AC 488 ms
64,512 KB
testcase_08 AC 503 ms
64,384 KB
testcase_09 AC 497 ms
64,512 KB
testcase_10 AC 499 ms
64,384 KB
testcase_11 AC 497 ms
64,640 KB
testcase_12 AC 506 ms
64,512 KB
testcase_13 AC 505 ms
64,512 KB
testcase_14 AC 497 ms
64,512 KB
testcase_15 AC 119 ms
17,792 KB
testcase_16 AC 246 ms
53,248 KB
testcase_17 AC 174 ms
32,896 KB
testcase_18 AC 149 ms
25,472 KB
testcase_19 AC 216 ms
45,056 KB
testcase_20 AC 504 ms
64,384 KB
testcase_21 AC 187 ms
34,944 KB
testcase_22 AC 503 ms
64,512 KB
testcase_23 AC 492 ms
64,512 KB
testcase_24 AC 483 ms
64,512 KB
testcase_25 AC 489 ms
64,512 KB
testcase_26 AC 488 ms
64,512 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 # 

#ifdef LOCAL
    #define _GLIBCXX_DEBUG
    #define __clock__
#else
    #pragma GCC optimize("Ofast")
#endif
#include<bits/stdc++.h>
using namespace std;
using ll = long long;
using ld = long double;
using VI = vector<ll>;
using VV = vector<VI>;
using VS = vector<string>;
using PII = pair<ll, ll>;

// 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 << '\n'; }

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)<<'\n'
#define p2(s, t) cout << (s) << " " << (t) << '\n'
#define br() p("")
#define pn(s) cout << (#s) << " " << (s) << '\n'
#define SZ(x) ((int)(x).size())
#define SORT(A) sort(ALL(A))
#define RSORT(A) sort(ALL(A), greater<ll>())
#define MP make_pair
#define p_yes() p("Yes")
#define p_no() p("No")

ll SUM(VI& V){
  return accumulate(ALL(V), 0LL);
}

ll MIN(VI& V){return *min_element(ALL(V));}
ll MAX(VI& V){return *max_element(ALL(V));}

void print_vector(VI& V){
  ll n = V.size();
  rep(i, n){
    if(i) cout << ' ';
    cout << V[i];
  }
  cout << endl;
}

ll gcd(ll a,ll b){
    if(b == 0) return a;
    return gcd(b,a%b);
}

ll lcm(ll a,ll b){
    ll g = gcd(a,b);
    return a / g * b;
}

// long double
using ld = long double;
#define EPS (1e-14)
#define equals(a,b) (fabs((a)-(b)) < EPS)

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

const ll mod = 1e9 + 7;
const ll inf = 1e18;
const double PI = acos(-1);

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((ll)d.size()<=i) return -1;
        return d[i];
    }
 
    void print_graph(){
        FOR(i, 0, (ll)graph.size()){
            cout << i << " -> ";
 
            for(auto edge : graph[i]){
                cout << edge.to << " ";
            }
            cout << endl;
        }
        p("distance");
        FOR(i, 0, (ll)graph.size()){
            ll d = distance(i);
            cout << i << " " << d << endl;
        }
    }
 
    void register_edge(ll a, ll b, ll cost){
        if(cost<0){
            p("ダイクストラなのに負コストですがいいですか？");exit(0);
        }
        auto edge = Edge(b, cost);
        graph[a].push_back(edge);
    }
 
    // 双方向
    void register_edge2(ll a, ll b, ll cost){
      register_edge(a, b, cost);
      register_edge(b, a, cost);
    }
 
    void calc_shortest_path(ll from=0){
      ll N = graph.size();
      if(from<0 || from>=N){
        cout << "index error" << endl;
        exit(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));
                }
            }
        }
    }
};

// LCA set
VV G;
const int N_MAX = 200010;
const int MAX_LOG_V = 20; // log2(200000)=17.6
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;
 
    for(ll to : G[index]){
        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, ll root=0){
    dfs(root, -1, 0);
    // ダブリングで親 2^k
    FOR(k, 1, MAX_LOG_V){
      // FOR(i, 1, N+1){
      FOR(i, 0, N){
        ll p = parent[k-1][i];
        if(p==-1) continue;
        parent[k][i] = parent[k-1][p];
      }
    }
}
// LCA set end

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

    // input
    ll N; 
    cin>>N;

    G.resize(N); // 距離情報なし
    Dijkstra dij; dij.initialize(N);
    
    rep(i,N-1){
      ll a,b,c;cin>>a>>b>>c;
      a--;b--;
      G[a].push_back(b);
      G[b].push_back(a);
      dij.register_edge2(a,b,c);
    }
    prepare_LCA(N, 0);
    dij.calc_shortest_path(0);

    ll Q;cin>>Q;
    while(Q--){
      ll u,v;cin>>u>>v;
      u--;v--;

      ll lca = LCA(u,v);
      ll dist = dij.distance(u) + dij.distance(v) - 2*dij.distance(lca);
      p(dist);
    }
    
    return 0;
}
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