結果

問題 No.2115 Making Forest Easy
ユーザー 👑 Nachia
提出日時 2022-10-28 23:19:24
言語 C++17(gcc12)
(gcc 12.3.0 + boost 1.87.0)
結果
AC  
実行時間 606 ms / 2,000 ms
コード長 7,483 bytes
コンパイル時間 3,499 ms
コンパイル使用メモリ 134,728 KB
最終ジャッジ日時 2025-02-08 15:13:07
ジャッジサーバーID
(参考情報)
judge3 / judge2
このコードへのチャレンジ
(要ログイン)
ファイルパターン 結果
sample AC * 2
other AC * 50
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 #
プレゼンテーションモードにする

#line 1 "Main.cpp"
#include <iostream>
#include <string>
#include <vector>
#include <algorithm>
#include <utility>
#include <atcoder/modint>
#line 4 "nachia\\graph\\graph.hpp"
#include <cassert>
#line 5 "nachia\\array\\csr-array.hpp"
namespace nachia{
template<class Elem>
class CsrArray{
public:
struct ListRange{
using iterator = typename std::vector<Elem>::iterator;
iterator begi, endi;
iterator begin() const { return begi; }
iterator end() const { return endi; }
int size() const { return (int)std::distance(begi, endi); }
Elem& operator[](int i) const { return begi[i]; }
};
struct ConstListRange{
using iterator = typename std::vector<Elem>::const_iterator;
iterator begi, endi;
iterator begin() const { return begi; }
iterator end() const { return endi; }
int size() const { return (int)std::distance(begi, endi); }
const Elem& operator[](int i) const { return begi[i]; }
};
private:
int m_n;
std::vector<Elem> m_list;
std::vector<int> m_pos;
public:
CsrArray() : m_n(0), m_list(), m_pos() {}
static CsrArray Construct(int n, std::vector<std::pair<int, Elem>> items){
CsrArray res;
res.m_n = n;
std::vector<int> buf(n+1, 0);
for(auto& [u,v] : items){ ++buf[u]; }
for(int i=1; i<=n; i++) buf[i] += buf[i-1];
res.m_list.resize(buf[n]);
for(int i=(int)items.size()-1; i>=0; i--){
res.m_list[--buf[items[i].first]] = std::move(items[i].second);
}
res.m_pos = std::move(buf);
return res;
}
static CsrArray FromRaw(std::vector<Elem> list, std::vector<int> pos){
CsrArray res;
res.m_n = pos.size() - 1;
res.m_list = std::move(list);
res.m_pos = std::move(pos);
return res;
}
ListRange operator[](int u) { return ListRange{ m_list.begin() + m_pos[u], m_list.begin() + m_pos[u+1] }; }
ConstListRange operator[](int u) const { return ConstListRange{ m_list.begin() + m_pos[u], m_list.begin() + m_pos[u+1] }; }
int size() const { return m_n; }
int fullSize() const { return (int)m_list.size(); }
};
} // namespace nachia
#line 6 "nachia\\graph\\graph.hpp"
namespace nachia{
struct Graph {
public:
struct Edge{
int from, to;
void reverse(){ std::swap(from, to); }
};
using Base = std::vector<std::pair<int, int>>;
Graph(int n = 0, bool undirected = false) : m_n(n), m_e(), m_isUndir(undirected) {}
Graph(int n, const std::vector<std::pair<int, int>>& edges, bool undirected = false) : m_n(n), m_isUndir(undirected){
m_e.resize(edges.size());
for(std::size_t i=0; i<edges.size(); i++) m_e[i] = { edges[i].first, edges[i].second };
}
Graph(int n, const std::vector<Edge>& edges, bool undirected = false) : m_n(n), m_e(edges), m_isUndir(undirected) {}
Graph(int n, std::vector<Edge>&& edges, bool undirected = false) : m_n(n), m_e(edges), m_isUndir(undirected) {}
int numVertices() const noexcept { return m_n; }
int numEdges() const noexcept { return int(m_e.size()); }
int addEdge(int from, int to){ m_e.push_back({ from, to }); return numEdges() - 1; }
Edge& operator[](int ei) noexcept { return m_e[ei]; }
const Edge& operator[](int ei) const noexcept { return m_e[ei]; }
Edge& at(int ei) { return m_e.at(ei); }
const Edge& at(int ei) const { return m_e.at(ei); }
auto begin(){ return m_e.begin(); }
auto end(){ return m_e.end(); }
auto begin() const { return m_e.begin(); }
auto end() const { return m_e.end(); }
bool isUndirected() const noexcept { return m_isUndir; }
void reverseEdges() noexcept { for(auto& e : m_e) e.reverse(); }
void contract(int newV, const std::vector<int>& mapping){
assert(numVertices() == int(mapping.size()));
for(int i=0; i<numVertices(); i++) assert(0 <= mapping[i] && mapping[i] < newV);
for(auto& e : m_e){ e.from = mapping[e.from]; e.to = mapping[e.to]; }
}
std::vector<Graph> induce(int num, const std::vector<int>& mapping) const {
int n = numVertices();
assert(n == int(mapping.size()));
for(int i=0; i<n; i++) assert(-1 <= mapping[i] && mapping[i] < num);
std::vector<int> indexV(n), newV(num);
for(int i=0; i<n; i++) if(mapping[i] >= 0) indexV[i] = ++newV[mapping[i]];
std::vector<Graph> res; res.reserve(num);
for(int i=0; i<num; i++) res.emplace_back(newV[i], isUndirected());
for(auto e : m_e) if(mapping[e.from] == mapping[e.to] && mapping[e.to] >= 0) res[mapping[e.to]].addEdge(indexV[e.from], indexV[e.to]);
return res;
}
CsrArray<int> getEdgeIndexArray(bool undirected) const {
std::vector<std::pair<int, int>> src;
src.reserve(numEdges() * (undirected ? 2 : 1));
for(int i=0; i<numEdges(); i++){
auto e = operator[](i);
src.emplace_back(e.from, i);
if(undirected) src.emplace_back(e.to, i);
}
return CsrArray<int>::Construct(numVertices(), src);
}
CsrArray<int> getEdgeIndexArray() const { return getEdgeIndexArray(isUndirected()); }
CsrArray<int> getAdjacencyArray(bool undirected) const {
std::vector<std::pair<int, int>> src;
src.reserve(numEdges() * (undirected ? 2 : 1));
for(auto e : m_e){
src.emplace_back(e.from, e.to);
if(undirected) src.emplace_back(e.to, e.from);
}
return CsrArray<int>::Construct(numVertices(), src);
}
CsrArray<int> getAdjacencyArray() const { return getAdjacencyArray(isUndirected()); }
private:
int m_n;
std::vector<Edge> m_e;
bool m_isUndir;
};
} // namespace nachia
#line 8 "Main.cpp"
using namespace std;
using i32 = int32_t;
using u32 = uint32_t;
using i64 = int64_t;
using u64 = uint64_t;
#define rep(i,n) for(int i=0; i<(int)(n); i++)
const i64 INF = 1001001001001001001;
using Modint = atcoder::static_modint<998244353>;
int main(){
int N; cin >> N;
vector<Modint> A(N);
rep(i,N){ int a; cin >> a; A[i] = Modint::raw(a); }
nachia::Graph G(N);
rep(i,N-1){ int u,v; cin >> u >> v; G.addEdge(u-1, v-1); }
auto adj = G.getAdjacencyArray(true);
vector<int> closed(N, 0);
vector<int> ord(N); rep(i,N) ord[i] = i;
sort(ord.begin(), ord.end(), [&](int l, int r){ return A[l].val() > A[r].val(); });
Modint INV2 = Modint(2).inv();
vector<int> bfs(N);
vector<int> par(N);
vector<Modint> dpE(N);
vector<Modint> dpX(N);
Modint anssum = 0;
Modint off = Modint(2).pow(N-1);
for(int v : ord){
int p2=0;
fill(par.begin(), par.end(), -1);
fill(dpE.begin(), dpE.end(), Modint(1));
fill(dpX.begin(), dpX.end(), Modint(1));
bfs[p2++] = v;
for(int w : bfs) for(int x : adj[w]) if(par[w] != x){ bfs[p2++] = x; par[x] = w; }
for(int i=N-1; i>=1; i--){
int w = bfs[i], p = par[w];
if(closed[w]){ dpX[w] = 0; dpE[w] = 0; }
Modint xw = 1 - (1 - dpX[w]) * INV2;
dpE[p] = dpE[w] * INV2 * dpX[p] + dpE[p] * xw;
dpX[p] *= xw;
}
Modint ans = dpE[v] * off;
anssum += ans * A[v];
closed[v] = 1;
}
cout << anssum.val() << endl;
return 0;
}
struct ios_do_not_sync{
ios_do_not_sync(){
std::ios::sync_with_stdio(false);
std::cin.tie(nullptr);
}
} ios_do_not_sync_instance;
הההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההה
XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
0