結果

問題 No.399 動的な領主
コンテスト
ユーザー 👑 binap
提出日時 2024-10-12 02:53:19
言語 C++17
(gcc 13.3.0 + boost 1.87.0)
結果
AC  
実行時間 571 ms / 2,000 ms
コード長 6,811 bytes
コンパイル時間 4,852 ms
コンパイル使用メモリ 265,028 KB
最終ジャッジ日時 2025-02-24 17:24:19
ジャッジサーバーID
（参考情報） 		judge4 / judge3
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ファイルパターン 結果
other AC * 19
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ソースコード

diff # 

#include<bits/stdc++.h>
#include<atcoder/all>
#define rep(i,n) for(int i=0;i<n;i++)
using namespace std;
using namespace atcoder;
typedef long long ll;
typedef vector<int> vi;
typedef vector<long long> vl;
typedef vector<vector<int>> vvi;
typedef vector<vector<long long>> vvl;
typedef long double ld;
typedef pair<int, int> P;

template <int m> ostream& operator<<(ostream& os, const static_modint<m>& a) {os << a.val(); return os;}
template <int m> ostream& operator<<(ostream& os, const dynamic_modint<m>& a) {os << a.val(); return os;}
template <int m> istream& operator>>(istream& is, static_modint<m>& a) {long long x; is >> x; a = x; return is;}
template <int m> istream& operator>>(istream& is, dynamic_modint<m>& a) {long long x; is >> x; a = x; return is;}
template<typename T> istream& operator>>(istream& is, vector<T>& v){int n = v.size(); assert(n > 0); rep(i, n) is >> v[i]; return is;}
template<typename U, typename T> ostream& operator<<(ostream& os, const pair<U, T>& p){os << p.first << ' ' << p.second; return os;}
template<typename T> ostream& operator<<(ostream& os, const vector<T>& v){int n = v.size(); rep(i, n) os << v[i] << (i == n - 1 ? "\n" : " "); return os;}
template<typename T> ostream& operator<<(ostream& os, const vector<vector<T>>& v){int n = v.size(); rep(i, n) os << v[i] << (i == n - 1 ? "\n" : ""); return os;}
template<typename T> ostream& operator<<(ostream& os, const set<T>& se){for(T x : se) os << x << " "; os << "\n"; return os;}
template<typename T> ostream& operator<<(ostream& os, const unordered_set<T>& se){for(T x : se) os << x << " "; os << "\n"; return os;}
template<typename S, auto op, auto e> ostream& operator<<(ostream& os, const atcoder::segtree<S, op, e>& seg){int n = seg.max_right(0, [](S){return true;}); rep(i, n) os << seg.get(i) << (i == n - 1 ? "\n" : " "); return os;}
template<typename S, auto op, auto e, typename F, auto mapping, auto composition, auto id> ostream& operator<<(ostream& os, const atcoder::lazy_segtree<S, op, e, F, mapping, composition, id>& seg){int n = seg.max_right(0, [](S){return true;}); rep(i, n) os << seg.get(i) << (i == n - 1 ? "\n" : " "); return os;}

template<typename T> void chmin(T& a, T b){a = min(a, b);}
template<typename T> void chmax(T& a, T b){a = max(a, b);}

// Lowest Common Ancestor by binary lifting
// https://youtu.be/8uowVvQ_-Mo?t=4306
template<typename T=int> // T: type of cost
struct lca {
  int n, root, l;
  vector<vector<int>> to;
  vector<vector<T>> co;
  vector<int> dep;
  vector<T> costs;
  vector<vector<int>> par;
  lca(int n):n(n),to(n),co(n),dep(n),costs(n) {
    l = 0;
    while ((1<<l) < n) ++l;
    par = vector<vector<int>>(n+1,vector<int>(l,n));
  }
  void addEdge(int a, int b, T c=0) {
    to[a].push_back(b); co[a].push_back(c);
    to[b].push_back(a); co[b].push_back(c);
  }
  void dfs(int v, int d=0, T c=0, int p=-1) {
    if (p != -1) par[v][0] = p;
    dep[v] = d;
    costs[v] = c;
    for (int i = 0; i < to[v].size(); ++i) {
      int u = to[v][i];
      if (u == p) continue;
      dfs(u, d+1, c+co[v][i], v);
    }
  }

  void init(int _root=0) {
    root = _root;
    dfs(root);
    for (int i = 0; i < l-1; ++i) {
      for (int v = 0; v < n; ++v) {
        par[v][i+1] = par[par[v][i]][i];
      }
    }
  }
  // LCA
  int up(int v, int k) {
    for (int i = l-1; i >= 0; --i) {
      int len = 1<<i;
      if (k >= len) k -= len, v = par[v][i];
    }
    return v;
  }
  int operator()(int a, int b) {
    if (dep[a] > dep[b]) swap(a,b);
    b = up(b, dep[b]-dep[a]);
    if (a == b) return a;
    for (int i = l-1; i >= 0; --i) {
      int na = par[a][i], nb = par[b][i];
      if (na != nb) a = na, b = nb;
    }
    return par[a][0];
  }
  int length(int a, int b) {
    int c = (*this)(a,b);
    return dep[a]+dep[b]-dep[c]*2;
  }
  T dist(int a, int b) {
    int c = (*this)(a,b);
    return costs[a]+costs[b]-costs[c]*2;
  }
};

using S = long long;
S op(S a, S b){
	return a + b;
}
S e(){
	return 0LL;
}

int main(){
	int n;
	cin >> n;
	vector<vector<int>> G(n);
	lca lca_graph(n);
	rep(i, n - 1){
		int u, v;
		cin >> u >> v;
		u--; v--;
		G[u].push_back(v);
		G[v].push_back(u);
		lca_graph.addEdge(u, v);
	}
	lca_graph.init();
	vector<vector<int>> children(n);
	vector<int> sz(n);
	vector<int> parent(n, -1);
	auto dfs_sz = [&](auto self, int from, int prev) -> int{
		int res = 1;
		for(int to : G[from]){
			if(to == prev) continue;
			children[from].push_back(to);
			parent[to] = from;
			res += self(self, to, from);
		}
		return sz[from] = res;
	};
	dfs_sz(dfs_sz, 0, -1);
	
	vector<int> belong_major(n, -1);
	vector<int> belong_minor(n, -1);
	vector<int> parent_light(n, -1);
	vector<int> length(n);
	
	vector<segtree<S, op, e>> seg;
	
	auto dfs_decompose = [&](auto self, int from, int prev) -> void{
		sort(children[from].begin(), children[from].end(), [&](int u, int v){
			return sz[u] > sz[v];
		});
		if(children[from].size()){
			// heavy edge
			{
				int to = children[from][0];
				parent_light[to] = prev;
				belong_major[to] = belong_major[from];
				belong_minor[to] = belong_minor[from] + 1;
				length[belong_major[to]]++;
				self(self, to, prev);
			}
			//	light edge
			for(int dir = 1; dir < int(children[from].size()); dir++){
				int to = children[from][dir];
				parent_light[to] = from;
				belong_major[to] = to;
				belong_minor[to] = 0;
				length[belong_major[to]]++;
				self(self, to, from);
			}
		}
	};
	belong_major[0] = 0;
	belong_minor[0] = 0;
	length[0] = 1;
	dfs_decompose(dfs_decompose, 0, -1);
	
	rep(i, n){
		vector<long long> init(length[i], 0LL);
		seg.emplace_back(init);
	}
	
	int q;
	cin >> q;
	
	auto add = [&](auto self, int x, long long c = 1) -> void{
		if(x == -1) return;
		int idx_major = belong_major[x];
		int idx_minor = belong_minor[x];
		
		{
			long long val = seg[idx_major].get(0);
			seg[idx_major].set(0, val + c);
		}
		if(idx_minor + 1 < length[idx_major]){
			long long val = seg[idx_major].get(idx_minor + 1);
			seg[idx_major].set(idx_minor + 1, val - c);
		}
		self(self, parent_light[x], c);
	};
	
	rep(_, q){
		int a, b;
		cin >> a >> b;
		a--; b--;
		add(add, a, 1);
		add(add, b, 1);
		int c = lca_graph(a, b);
		add(add, c, -1);
		add(add, parent[c], -1);
	}
	
	auto c2 = [&](long long x){return x * (x + 1) / 2;};
	long long ans = 0;
	auto dfs_calc = [&](auto self, int from, long long val) -> void{
		int idx_major = belong_major[from];
		int idx_minor = belong_minor[from];
		val += seg[idx_major].get(idx_minor);
		ans += c2(val);
		if(children[from].size()){
			// heavy edge
			{
				int to = children[from][0];
				self(self, to, val);
			}
			//	light edge
			for(int dir = 1; dir < int(children[from].size()); dir++){
				int to = children[from][dir];
				self(self, to, 0LL);
			}
		}
	};
	dfs_calc(dfs_calc, 0, 0LL);
	cout << ans << "\n";
	return 0;
}
0