mmrz's library

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verify/aoj/grl/5_C.test.cpp

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• Last update: 2025-07-01 03:22:56+09:00
• Problem: https://judge.u-aizu.ac.jp/onlinejudge/description.jsp?id=GRL_5_C

Depends on

• Lowest Common Ancestor (graph/lowest_common_ancestor.hpp)
• template/template.hpp

Code

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

#include "./../../../template/template.hpp"
#include "./../../../graph/lowest_common_ancestor.hpp"

using namespace mmrz;

void mmrz::solve(){
	int n;
	cin >> n;
	vector<vector<int>> g(n);
	rep(i, n){
		int k;
		cin >> k;
		while(k--){
			int c;
			cin >> c;
			g[i].pb(c);
			g[c].pb(i);
		}
	}

	lowest_common_ancestor lca(g, 0);

	int q;
	cin >> q;
	while(q--){
		int u, v;
		cin >> u >> v;
		cout << lca.get(u, v) << '\n';
	}
}

#line 1 "verify/aoj/grl/5_C.test.cpp"
#define PROBLEM "https://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 ll = long long;
using ull = unsigned long long;
const double pi = acos(-1);
template<class T>constexpr T inf() { return ::std::numeric_limits<T>::max(); }
template<class T>constexpr T hinf() { return inf<T>() / 2; }
template <typename T_char>T_char TL(T_char cX) { return tolower(cX); }
template <typename T_char>T_char TU(T_char cX) { return toupper(cX); }
template<class T> bool chmin(T& a,T b) { if(a > b){a = b; return true;} return false; }
template<class T> bool chmax(T& a,T b) { if(a < b){a = b; return true;} return false; }
int popcnt(unsigned long long n) { int cnt = 0; for (int i = 0; i < 64; i++)if ((n >> i) & 1)cnt++; return cnt; }
int d_sum(ll n) { int ret = 0; while (n > 0) { ret += n % 10; n /= 10; }return ret; }
int d_cnt(ll n) { int ret = 0; while (n > 0) { ret++; n /= 10; }return ret; }
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; };
ll MOD(ll x, ll m){return (x%m+m)%m; }
ll FLOOR(ll x, ll m) {ll r = (x%m+m)%m; return (x-r)/m; }
template<class T> using dijk = priority_queue<T, vector<T>, greater<T>>;
# define all(qpqpq)           (qpqpq).begin(),(qpqpq).end()
# define UNIQUE(wpwpw)        (wpwpw).erase(unique(all((wpwpw))),(wpwpw).end())
# define LOWER(epepe)         transform(all((epepe)),(epepe).begin(),TL<char>)
# define UPPER(rprpr)         transform(all((rprpr)),(rprpr).begin(),TU<char>)
# define rep(i,upupu)         for(ll i = 0, i##_len = (upupu);(i) < (i##_len);(i)++)
# define reps(i,opopo)        for(ll i = 1, i##_len = (opopo);(i) <= (i##_len);(i)++)
# define len(x)                ((ll)(x).size())
# define bit(n)               (1LL << (n))
# define pb push_back
# define eb emplace_back
# define exists(c, e)         ((c).find(e) != (c).end())

struct INIT{
	INIT(){
		std::ios::sync_with_stdio(false);
		std::cin.tie(0);
		cout << fixed << setprecision(20);
	}
}INIT;

namespace mmrz {
	void solve();
}

int main(){
	mmrz::solve();
}
#line 2 "graph/lowest_common_ancestor.hpp"

#line 4 "graph/lowest_common_ancestor.hpp"

struct lowest_common_ancestor {
private:
	int n;
	int root;
	std::vector<std::vector<int>>par;
public:
	std::vector<int>depth;

	lowest_common_ancestor(std::vector<std::vector<int>>& g, int Root) : n((int)g.size()) {
		depth.resize(n);
		par.resize(n);
		for (int i = 0; i < n; i++)par[i].resize(31);
		root = Root;

		auto dfs = [&](auto f, int v, int p, int d) -> void {
			par[v][0] = p;
			depth[v] = d;
			for(size_t i = 0;i < g[v].size();i++){
				if(g[v][i] == p)continue;
				f(f, g[v][i], v, d+1);
			}
		};

		dfs(dfs, root, -1, 0);
		
		for (int i = 0; i < 30; i++) {
			for (int j = 0; j < n; j++) {
				if (par[j][i] == -1)par[j][i + 1] = -1;
				else par[j][i + 1] = par[par[j][i]][i];
			}
		}
	}

	int get(int u, int v) {
		if (depth[u] > depth[v])std::swap(u, v);
		for (int i = 30; i >= 0; i--) {
			if (((depth[v] - depth[u]) >> i) & 1) {
				v = par[v][i];
			}
		}
		if (u == v)return u;

		for (int i = 30; i >= 0; i--) {
			if (par[u][i] != par[v][i]) {
				u = par[u][i];
				v = par[v][i];
			}
		}
		return par[u][0];
	}
};
#line 5 "verify/aoj/grl/5_C.test.cpp"

using namespace mmrz;

void mmrz::solve(){
	int n;
	cin >> n;
	vector<vector<int>> g(n);
	rep(i, n){
		int k;
		cin >> k;
		while(k--){
			int c;
			cin >> c;
			g[i].pb(c);
			g[c].pb(i);
		}
	}

	lowest_common_ancestor lca(g, 0);

	int q;
	cin >> q;
	while(q--){
		int u, v;
		cin >> u >> v;
		cout << lca.get(u, v) << '\n';
	}
}

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