結果

問題 No.3194 Do Optimize Your Solution
ユーザー 👑 Nachia
提出日時 2025-06-27 22:31:52
言語 C++17
(gcc 13.3.0 + boost 1.87.0)
結果
AC  
実行時間 2,644 ms / 3,000 ms
コード長 10,335 bytes
コンパイル時間 1,548 ms
コンパイル使用メモリ 102,432 KB
実行使用メモリ 98,540 KB
最終ジャッジ日時 2025-06-27 22:32:23
合計ジャッジ時間 8,455 ms
ジャッジサーバーID
（参考情報） 		judge2 / judge3
このコードへのチャレンジ
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ファイルパターン 結果
sample AC * 2
other AC * 17
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 NACHIA
#define _GLIBCXX_DEBUG
#else
#define NDEBUG
#endif
#include <iostream>
#include <string>
#include <vector>
#include <algorithm>
#include <array>
using i64 = long long;
using u64 = unsigned long long;
#define rep(i,n) for(i64 i=0; i<i64(n); i++)
const i64 INF = 1001001001001001001;
template<typename A> void chmin(A& l, const A& r){ if(r < l) l = r; }
template<typename A> void chmax(A& l, const A& r){ if(l < r) l = r; }
using namespace std;

#include <utility>
#include <cassert>

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

namespace nachia{


struct Graph {
public:
    struct Edge{
        int from, to;
        void reverse(){ std::swap(from, to); }
        int xorval() const { return from ^ to; }
    };
    Graph() : m_n(0), m_e(0), m_isUndir(false) {}
    explicit Graph(int n, bool undirected = false, int m = 0) : m_n(n), m_e(m), m_isUndir(undirected) {}
    explicit Graph(int n, const std::vector<std::pair<int, int>>& edges, int 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 };
    }
    template<class Cin>
    static Graph Input(Cin& cin, int n, bool undirected, int m, int offset = 0){
        Graph res(n, undirected, m);
        for(int i=0; i<m; i++){
            int u, v; cin >> u >> v;
            res[i].from = u - offset;
            res[i].to = v - offset;
        }
        return res;
    }
    int numVertices() const noexcept { return m_n; }
    int numEdges() const noexcept { return int(m_e.size()); }
    int addNode() noexcept { return m_n++; }
    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]; }
        m_n = newV;
    }
    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

void testcase(){
    int N; cin >> N;
    auto A = nachia::Graph::Input(cin, N, true, N-1, 1).getAdjacencyArray();
    auto B = nachia::Graph::Input(cin, N, true, N-1, 1).getAdjacencyArray();

    auto dobfs = [&](int N, vector<int>& par, vector<int>& sz, auto& adj, int s){
        par.assign(N, -1);
        sz.assign(N, 1);
        vector<int> bfs; bfs.push_back(s);
        rep(i,bfs.size()){
            int v = bfs[i];
            for(int w : adj[v]) if(par[v] != w){
                par[w] = v; bfs.push_back(w);
            }
        }
        for(int i=bfs.size()-1; i>=1; i--) sz[par[bfs[i]]] += sz[bfs[i]];
    };

    auto src_cent = [&](vector<int>& par, vector<int>& sz, auto& adj, int& v){
        while(true){
            int nx = -1;
            for(int w : adj[v]) if(sz[v] < sz[w] * 2){
                sz[v] -= sz[w]; sz[w] += sz[v]; par[w] = -1; par[v] = w;
                nx = w; break;
            }
            if(nx < 0) break;
            v = nx;
        }
    };

    vector<int> parCB(N, -1), depCB(N);
    vector<vector<int>> distB(20, vector<int>(N,-1));
    int cdBroot = 0;
    {
        vector<int> par, sz; dobfs(N, par, sz, B, 0);
        auto cdB = [&](auto& self, int v, int cddep) -> int {
            src_cent(par, sz, B, v);
            sz[v] = 0;
            depCB[v] = cddep;
            vector<int> bfs = {v}; distB[cddep][v] = 0;
            rep(i,bfs.size()){
                int x = bfs[i];
                for(int y : B[x]) if(sz[y] > 0 && distB[cddep][y] < 0){
                    distB[cddep][y] = distB[cddep][x] + 1;
                    bfs.push_back(y);
                }
            }
            for(int w : B[v]) if(sz[w]){
                par[w] = -1;
                parCB[self(self, w, cddep + 1)] = v;
            }
            return v;
        };
        cdBroot = cdB(cdB, 0, 1);
        rep(i,N) distB[0][i] = 0;
    }

    vector<int> cdBpathSep(N+1);
    vector<pair<int,u64>> cdBpath;
    rep(v,N){
        for(int p=v; p>=0; p=parCB[p]){
            u64 d = distB[depCB[p]][v] - distB[depCB[p]-1][v];
            cdBpath.push_back({ p, d });
        }
        cdBpathSep[v+1] = cdBpath.size();
    }

    vector<int> dsmem;
    vector<array<u64,4>> ds(N);
    auto add = [&](int v, u64 w) -> void {
        int l = cdBpathSep[v], r = cdBpathSep[v+1];
        rep(i,r-l){
            auto [p,d] = cdBpath[l+i];
            ds[p][0] += 1;
            ds[p][1] += d;
            ds[p][2] += w;
            ds[p][3] += d * w;
        }
        dsmem.push_back(v);
    };
    auto sum = [&](int v, u64 w) -> u64 {
        u64 res = 0;
        int l = cdBpathSep[v], r = cdBpathSep[v+1];
        u64 p0 = 0, p2 = 0;
        rep(i,r-l){
            auto [p,d] = cdBpath[l+i];
            res += (ds[p][0] - p0) * w * distB[depCB[p]][v];
            res += ds[p][1] * w;
            res += (ds[p][2] - p2) * distB[depCB[p]][v];
            res += ds[p][3];
            p0 = ds[p][0]; p2 = ds[p][2];
        }
        return res;
    };
    auto clr = [&]() -> void {
        for(int v : dsmem){
            int l = cdBpathSep[v], r = cdBpathSep[v+1];
            rep(i,r-l) ds[cdBpath[l+i].first].fill(0);
        }
        dsmem.clear();
    };

    u64 ans = 0;

    {
        vector<int> par, sz; dobfs(N, par, sz, A, 0);
        vector<int> dist(N);
        auto cdA = [&](auto& self, int v) -> void {
            src_cent(par, sz, A, v);
            sz[v] = 0;
            add(v, 0);
            for(int sv : A[v]) if(sz[sv]){
                vector<int> bfs = {sv};
                dist[sv] = 1;
                rep(i,bfs.size()) for(int y : A[bfs[i]]) if(par[y] == bfs[i]){
                    dist[y] = dist[bfs[i]] + 1;
                    bfs.push_back(y);
                }
                for(int x : bfs) ans += sum(x, dist[x]);
                for(int x : bfs) add(x, dist[x]);
            }
            clr();
            for(int w : A[v]) if(sz[w]){ par[w] = -1; self(self, w); }
        };
        cdA(cdA, 0);
    }
    
    ans *= 2;
    cout << ans << "\n";
}

int main(){
    ios::sync_with_stdio(false); cin.tie(nullptr);
    testcase();
    return 0;
}
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