#876044 (C++17) No.2337 Equidistant

提出ソース
結果

問題	No.2337 Equidistant
ユーザー	👑 Nachia
提出日時	2023-05-30 17:10:47
言語	C++17 (gcc 12.3.0 + boost 1.83.0)
結果	AC
実行時間	226 ms / 4,000 ms
コード長	14,234 bytes
コンパイル時間	1,637 ms
コンパイル使用メモリ	100,224 KB
実行使用メモリ	19,704 KB
最終ジャッジ日時	2024-06-08 20:20:54
合計ジャッジ時間	9,104 ms
ジャッジサーバーID （参考情報）	judge1 / judge4
このコードへのチャレンジ
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テストケース

テストケース表示
入力	結果	実行時間実行使用メモリ
testcase_00	AC	2 ms 5,248 KB
testcase_01	AC	2 ms 5,376 KB
testcase_02	AC	2 ms 5,376 KB
testcase_03	AC	2 ms 5,376 KB
testcase_04	AC	2 ms 5,376 KB
testcase_05	AC	2 ms 5,376 KB
testcase_06	AC	4 ms 5,376 KB
testcase_07	AC	3 ms 5,376 KB
testcase_08	AC	3 ms 5,376 KB
testcase_09	AC	3 ms 5,376 KB
testcase_10	AC	4 ms 5,376 KB
testcase_11	AC	204 ms 19,696 KB
testcase_12	AC	201 ms 19,572 KB
testcase_13	AC	199 ms 19,568 KB
testcase_14	AC	208 ms 19,700 KB
testcase_15	AC	210 ms 19,572 KB
testcase_16	AC	205 ms 19,700 KB
testcase_17	AC	200 ms 19,704 KB
testcase_18	AC	200 ms 19,608 KB
testcase_19	AC	203 ms 19,700 KB
testcase_20	AC	202 ms 19,696 KB
testcase_21	AC	171 ms 19,576 KB
testcase_22	AC	183 ms 19,700 KB
testcase_23	AC	176 ms 19,700 KB
testcase_24	AC	203 ms 19,700 KB
testcase_25	AC	185 ms 19,700 KB
testcase_26	AC	226 ms 19,704 KB
testcase_27	AC	202 ms 19,700 KB
testcase_28	AC	200 ms 19,572 KB
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ソースコード

raw source code
#line 1 "..\\Main.cpp"

#line 2 "D:\\Programming\\VSCode\\competitive-cpp\\nachia\\array\\csr-array.hpp"
#include <utility>
#include <vector>
#include <algorithm>

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 4 "D:\\Programming\\VSCode\\competitive-cpp\\nachia\\graph\\graph.hpp"
#include <cassert>
#line 6 "D:\\Programming\\VSCode\\competitive-cpp\\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, int m = 0) : m_n(n), m_e(m), 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 };
    }
    template<class Cin>
    static Graph Input(Cin& cin, int n, bool undirected, int m, bool 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
#line 6 "D:\\Programming\\VSCode\\competitive-cpp\\nachia\\tree\\heavy-light-decomposition.hpp"

namespace nachia{

struct HeavyLightDecomposition{
private:

    int N;
    std::vector<int> P;
    std::vector<int> PP;
    std::vector<int> PD;
    std::vector<int> D;
    std::vector<int> I;

    std::vector<int> rangeL;
    std::vector<int> rangeR;

public:

    HeavyLightDecomposition(const CsrArray<int>& E = CsrArray<int>::Construct(1, {}), int root = 0){
        N = E.size();
        P.assign(N, -1);
        I = {root};
        I.reserve(N);
        for(int i=0; i<(int)I.size(); i++){
            int p = I[i];
            for(int e : E[p]) if(P[p] != e){
                I.push_back(e);
                P[e] = p;
            }
        }
        std::vector<int> Z(N, 1);
        std::vector<int> nx(N, -1);
        PP.resize(N);
        for(int i=0; i<N; i++) PP[i] = i;
        for(int i=N-1; i>=1; i--){
            int p = I[i];
            Z[P[p]] += Z[p];
            if(nx[P[p]] == -1) nx[P[p]] = p;
            if(Z[nx[P[p]]] < Z[p]) nx[P[p]] = p;
        }

        for(int p : I) if(nx[p] != -1) PP[nx[p]] = p;

        PD.assign(N,N);
        PD[root] = 0;
        D.assign(N,0);
        for(int p : I) if(p != root){
            PP[p] = PP[PP[p]];
            PD[p] = std::min(PD[PP[p]], PD[P[p]]+1);
            D[p] = D[P[p]]+1;
        }
        
        rangeL.assign(N,0);
        rangeR.assign(N,0);
        
        for(int p : I){
            rangeR[p] = rangeL[p] + Z[p];
            int ir = rangeR[p];
            for(int e : E[p]) if(P[p] != e) if(e != nx[p]){
                rangeL[e] = (ir -= Z[e]);
            }
            if(nx[p] != -1){
                rangeL[nx[p]] = rangeL[p] + 1;
            }
        }

        I.resize(N);
        for(int i=0; i<N; i++) I[rangeL[i]] = i;
    }
    
    HeavyLightDecomposition(const Graph& tree, int root = 0)
        : HeavyLightDecomposition(tree.getAdjacencyArray(true), root) {}

    int numVertices() const { return N; }
    int depth(int p) const { return D[p]; }
    int toSeq(int vertex) const { return rangeL[vertex]; }
    int toVtx(int seqidx) const { return I[seqidx]; }
    int toSeq2In(int vertex) const { return rangeL[vertex] * 2 - D[vertex]; }
    int toSeq2Out(int vertex) const { return rangeR[vertex] * 2 - D[vertex] - 1; }
    int parentOf(int v) const { return P[v]; }
    int heavyRootOf(int v) const { return PP[v]; }
    int heavyChildOf(int v) const {
        if(toSeq(v) == N-1) return -1;
        int cand = toVtx(toSeq(v) + 1);
        if(PP[v] == PP[cand]) return cand;
        return -1;
    }

    int lca(int u, int v) const {
        if(PD[u] < PD[v]) std::swap(u, v);
        while(PD[u] > PD[v]) u = P[PP[u]];
        while(PP[u] != PP[v]){ u = P[PP[u]]; v = P[PP[v]]; }
        return (D[u] > D[v]) ? v : u;
    }

    int dist(int u, int v) const {
        return depth(u) + depth(v) - depth(lca(u,v)) * 2;
    }

    std::vector<std::pair<int,int>> path(int r, int c, bool include_root = true, bool reverse_path = false) const {
        if(PD[c] < PD[r]) return {};
        std::vector<std::pair<int,int>> res(PD[c]-PD[r]+1);
        for(int i=0; i<(int)res.size()-1; i++){
            res[i] = std::make_pair(rangeL[PP[c]], rangeL[c]+1);
            c = P[PP[c]];
        }
        if(PP[r] != PP[c] || D[r] > D[c]) return {};
        res.back() = std::make_pair(rangeL[r]+(include_root?0:1), rangeL[c]+1);
        if(res.back().first == res.back().second) res.pop_back();
        if(!reverse_path) std::reverse(res.begin(),res.end());
        else for(auto& a : res) a = std::make_pair(N - a.second, N - a.first);
        return res;
    }

    std::pair<int,int> subtree(int p){
        return std::make_pair(rangeL[p], rangeR[p]);
    }

    int median(int x, int y, int z) const {
        return lca(x,y) ^ lca(y,z) ^ lca(x,z);
    }

    int la(int from, int to, int d) const {
        if(d < 0) return -1;
        int g = lca(from,to);
        int dist0 = D[from] - D[g] * 2 + D[to];
        if(dist0 < d) return -1;
        int p = from;
        if(D[from] - D[g] < d){ p = to; d = dist0 - d; }
        while(D[p] - D[PP[p]] < d){
            d -= D[p] - D[PP[p]] + 1;
            p = P[PP[p]];
        }
        return I[rangeL[p] - d];
    }
};

} // namespace nachia
#line 6 "D:\\Programming\\VSCode\\competitive-cpp\\nachia\\tree\\tree-dp.hpp"
#include <type_traits>

namespace nachia{

template<
    class S,
    class RakeFunc,
    class CompressFunc,
    typename std::enable_if_t<std::is_invocable_r_v<S, RakeFunc, S, S>, void*> = nullptr,
    typename std::enable_if_t<std::is_invocable_r_v<S, CompressFunc, S, int, int>, void*> = nullptr
>
class TreeDP{
private:
    std::vector<S> low;
    std::vector<S> high;
    std::vector<int> XorEdge;
    std::vector<int> P;
    RakeFunc rake;
    CompressFunc compress;

public:

    // S rake(S a, S b)
    // S compress(S a, int edgeIndex, int newRoot)
    TreeDP(const Graph& tree, std::vector<S> node, RakeFunc _rake, CompressFunc _compress)
        : rake(std::move(_rake))
        , compress(std::move(_compress))
    {
        int n = tree.numVertices();
        auto adj = tree.getEdgeIndexArray(true);
        XorEdge.resize(n-1);
        for(int i=0; i<n-1; i++) XorEdge[i] = tree[i].from ^ tree[i].to;
        std::vector<int> bfs(n, 0);
        int bfsi = 1;
        P.assign(n, -1);
        for(int v : bfs){
            for(int e : adj[v]){
                int w = v ^ XorEdge[e];
                if(P[v] != e){ P[w] = e; bfs[bfsi++] = w; }
            }
        }
        low = node;
        for(int i=n-1; i>=1; i--){
            int w = bfs[i];
            int v = w ^ XorEdge[P[w]];
            low[v] = rake(low[v], compress(low[w], P[w], v));
        }
        
        high = node;
        for(int i=0; i<n; i++){
            int v = bfs[i];
            int C = adj[v].size();
            S fold = node[0];
            if(v != 0) fold = compress(high[v], P[v], v);
            for(int ci=C-1; ci>=0; ci--){
                int e = adj[v][ci];
                if(P[v] == e) continue;
                int w = v ^ XorEdge[e];
                high[w] = fold;
                fold = rake(compress(low[w], e, v), fold);
            }
            fold = node[v];
            for(int ci=0; ci<C; ci++){
                int e = adj[v][ci];
                if(P[v] == e) continue;
                int w = v ^ XorEdge[e];
                high[w] = rake(high[w], fold);
                fold = rake(fold, compress(low[w], e, v));
            }
        }
    }

    int edgeBetween(int u, int v){
        if(P[u] >= 0 && XorEdge[P[u]] == (u^v)) return P[u];
        return P[v];
    }

    S getAtVtx(int i){
        if(i == 0) return low[i];
        return rake(compress(high[i], P[i], i), low[i]);
    }
    S getAtEdge(int root, int edge){
        if(P[root] == edge) return low[root];
        return high[root ^ XorEdge[edge]];
    }
};

} // namespace nachia
#line 4 "..\\Main.cpp"
#include <iostream>
#include <string>
#line 8 "..\\Main.cpp"
#include <atcoder/modint>
using namespace std;
using i32 = int;
using u32 = unsigned int;
using i64 = long long;
using u64 = unsigned long long;
#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, Q; cin >> N >> Q;
    auto tree = nachia::Graph::Input(cin, N, true, N-1, 1);
    auto hld = nachia::HeavyLightDecomposition(tree);
    auto tree_dp = nachia::TreeDP(
        tree,
        vector<int>(N, 1),
        [&](int a, int b){ return a+b-1; },
        [&](int a, int, int){ return a+1; }
    );
    rep(q,Q){
        int s,t; cin >> s >> t; s--; t--;
        int d = hld.dist(s, t);
        if(d%2 == 1){ cout << "0\n"; continue; }
        int m = hld.la(s, t, d/2);
        int ms = hld.la(m, s, 1);
        int mt = hld.la(m, t, 1);
        int sz1 = tree_dp.getAtEdge(ms, tree_dp.edgeBetween(m, ms));
        int sz2 = tree_dp.getAtEdge(mt, tree_dp.edgeBetween(m, mt));
        int ans = N - sz1 - sz2;
        cout << ans << '\n';
    }
    return 0;
}



struct ios_do_not_sync{
    ios_do_not_sync(){
        ios::sync_with_stdio(false);
        cin.tie(nullptr);
    }
} ios_do_not_sync_instance;
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結果

テストケース

ソースコード
