test/verify/aoj-grl-5-c.test.cpp

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• Last update: 2022-09-11 00:53:50+09:00
• Problem: http://judge.u-aizu.ac.jp/onlinejudge/description.jsp?id=GRL_5_C

Depends on

• Graph Template(グラフテンプレート) (graph/graph-template.hpp)
• Doubling-Lowest-Common-Ancestor(最小共通祖先) (graph/tree/doubling-lowest-common-ancestor.hpp)
• template/template.hpp

Code

#define PROBLEM "http://judge.u-aizu.ac.jp/onlinejudge/description.jsp?id=GRL_5_C"

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

#include "../../graph/tree/doubling-lowest-common-ancestor.hpp"

int main() {
  int N, Q;
  cin >> N;
  DoublingLowestCommonAncestor< int > dlca(N);
  for(int i = 0; i < N; i++) {
    int k;
    cin >> k;
    for(int j = 0; j < k; j++) {
      int c;
      cin >> c;
      dlca.add_edge(i, c);
    }
  }
  dlca.build();
  cin >> Q;
  for(int i = 0; i < Q; i++) {
    int u, v;
    cin >> u >> v;
    cout << dlca.lca(u, v) << "\n";
  }
}

#line 1 "test/verify/aoj-grl-5-c.test.cpp"
#define PROBLEM "http://judge.u-aizu.ac.jp/onlinejudge/description.jsp?id=GRL_5_C"

#line 1 "template/template.hpp"
#include<bits/stdc++.h>

using namespace std;

using int64 = long long;
const int mod = 1e9 + 7;

const int64 infll = (1LL << 62) - 1;
const int inf = (1 << 30) - 1;

struct IoSetup {
  IoSetup() {
    cin.tie(nullptr);
    ios::sync_with_stdio(false);
    cout << fixed << setprecision(10);
    cerr << fixed << setprecision(10);
  }
} iosetup;

template< typename T1, typename T2 >
ostream &operator<<(ostream &os, const pair< T1, T2 >& p) {
  os << p.first << " " << p.second;
  return os;
}

template< typename T1, typename T2 >
istream &operator>>(istream &is, pair< T1, T2 > &p) {
  is >> p.first >> p.second;
  return is;
}

template< typename T >
ostream &operator<<(ostream &os, const vector< T > &v) {
  for(int i = 0; i < (int) v.size(); i++) {
    os << v[i] << (i + 1 != v.size() ? " " : "");
  }
  return os;
}

template< typename T >
istream &operator>>(istream &is, vector< T > &v) {
  for(T &in : v) is >> in;
  return is;
}

template< typename T1, typename T2 >
inline bool chmax(T1 &a, T2 b) { return a < b && (a = b, true); }

template< typename T1, typename T2 >
inline bool chmin(T1 &a, T2 b) { return a > b && (a = b, true); }

template< typename T = int64 >
vector< T > make_v(size_t a) {
  return vector< T >(a);
}

template< typename T, typename... Ts >
auto make_v(size_t a, Ts... ts) {
  return vector< decltype(make_v< T >(ts...)) >(a, make_v< T >(ts...));
}

template< typename T, typename V >
typename enable_if< is_class< T >::value == 0 >::type fill_v(T &t, const V &v) {
  t = v;
}

template< typename T, typename V >
typename enable_if< is_class< T >::value != 0 >::type fill_v(T &t, const V &v) {
  for(auto &e : t) fill_v(e, v);
}

template< typename F >
struct FixPoint : F {
  explicit FixPoint(F &&f) : F(forward< F >(f)) {}

  template< typename... Args >
  decltype(auto) operator()(Args &&... args) const {
    return F::operator()(*this, forward< Args >(args)...);
  }
};
 
template< typename F >
inline decltype(auto) MFP(F &&f) {
  return FixPoint< F >{forward< F >(f)};
}
#line 4 "test/verify/aoj-grl-5-c.test.cpp"

#line 2 "graph/tree/doubling-lowest-common-ancestor.hpp"

#line 2 "graph/graph-template.hpp"

/**
 * @brief Graph Template(グラフテンプレート)
 */
template< typename T = int >
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) {}

  operator int() const { return to; }
};

template< typename T = int >
struct Graph {
  vector< vector< Edge< T > > > g;
  int es;

  Graph() = default;

  explicit Graph(int n) : g(n), es(0) {}

  size_t size() const {
    return g.size();
  }

  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++);
  }

  void read(int M, int padding = -1, bool weighted = false, bool directed = false) {
    for(int i = 0; i < M; i++) {
      int a, b;
      cin >> a >> b;
      a += padding;
      b += padding;
      T c = T(1);
      if(weighted) cin >> c;
      if(directed) add_directed_edge(a, b, c);
      else add_edge(a, b, c);
    }
  }

  inline vector< Edge< T > > &operator[](const int &k) {
    return g[k];
  }

  inline const vector< Edge< T > > &operator[](const int &k) const {
    return g[k];
  }
};

template< typename T = int >
using Edges = vector< Edge< T > >;
#line 4 "graph/tree/doubling-lowest-common-ancestor.hpp"

/**
 * @brief Doubling-Lowest-Common-Ancestor(最小共通祖先)
 * @docs docs/doubling-lowest-common-ancestor.md
 */
template< typename T >
struct DoublingLowestCommonAncestor : Graph< T > {
public:
  using Graph< T >::g;
  vector< int > dep;
  vector< T > sum;
  vector< vector< int > > table;
  const int LOG;

  explicit DoublingLowestCommonAncestor(int n)
      : Graph< T >(n), LOG(32 - __builtin_clz(g.size())) {}

  explicit DoublingLowestCommonAncestor(const Graph< T > &g)
      : LOG(32 - __builtin_clz(g.size())), Graph< T >(g) {}

  void build(int root = 0) {
    dep.assign(g.size(), 0);
    sum.assign(g.size(), 0);
    table.assign(LOG, vector< int >(g.size(), -1));
    dfs(root, -1, 0);
    for(int k = 0; k + 1 < LOG; k++) {
      for(int i = 0; i < (int)table[k].size(); i++) {
        if(table[k][i] == -1) table[k + 1][i] = -1;
        else table[k + 1][i] = table[k][table[k][i]];
      }
    }
  }

  int lca(int u, int v) {
    if(dep[u] > dep[v]) swap(u, v);
    v = climb(v, dep[v] - dep[u]);
    if(u == v) return u;
    for(int i = LOG - 1; i >= 0; i--) {
      if(table[i][u] != table[i][v]) {
        u = table[i][u];
        v = table[i][v];
      }
    }
    return table[0][u];
  }

  int climb(int u, int k) {
    if(dep[u] < k) return -1;
    for(int i = LOG - 1; i >= 0; i--) {
      if((k >> i) & 1) u = table[i][u];
    }
    return u;
  }

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

private:
  void dfs(int idx, int par, int d) {
    table[0][idx] = par;
    dep[idx] = d;
    for(auto &to : g[idx]) {
      if(to != par) {
        sum[to] = sum[idx] + to.cost;
        dfs(to, idx, d + 1);
      }
    }
  }
};
#line 6 "test/verify/aoj-grl-5-c.test.cpp"

int main() {
  int N, Q;
  cin >> N;
  DoublingLowestCommonAncestor< int > dlca(N);
  for(int i = 0; i < N; i++) {
    int k;
    cin >> k;
    for(int j = 0; j < k; j++) {
      int c;
      cin >> c;
      dlca.add_edge(i, c);
    }
  }
  dlca.build();
  cin >> Q;
  for(int i = 0; i < Q; i++) {
    int u, v;
    cin >> u >> v;
    cout << dlca.lca(u, v) << "\n";
  }
}

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