結果
| 問題 | No.2674 k-Walk on Bipartite |
| ユーザー |
👑  Nachia
|
| 提出日時 | 2024-03-16 15:13:04 |
| 言語 | C++17 (gcc 13.3.0 + boost 1.87.0) |
| 結果 |
AC
|
| 実行時間 | 63 ms / 2,000 ms |
| コード長 | 9,147 bytes |
| コンパイル時間 | 1,526 ms |
| コンパイル使用メモリ | 113,800 KB |
| 最終ジャッジ日時 | 2025-02-20 06:50:24 |
|
ジャッジサーバーID （参考情報） |
judge3 / judge3 |
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| ファイルパターン | 結果 |
|---|---|
| sample | AC * 3 |
| other | AC * 36 |
ソースコード
#ifdef NACHIA#define _GLIBCXX_DEBUG#else#define NDEBUG#endif#include <iostream>#include <string>#include <vector>#include <algorithm>#include <utility>#include <queue>#include <array>#include <cmath>#include <atcoder/modint>using i64 = long long;using u64 = unsigned long long;#define rep(i,n) for(i64 i=0; i<(i64)(n); i++)#define repr(i,n) for(i64 i=(i64)(n)-1; i>=0; i--)const i64 INF = 1001001001001001001;const char* yn(bool x){ return x ? "Yes" : "No"; }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; }template<typename A> using nega_queue = std::priority_queue<A,std::vector<A>,std::greater<A>>;using Modint = atcoder::static_modint<998244353>;using namespace std;namespace nachia {struct DsuFast{private:std::vector<int> w;public:DsuFast(int n = 0) : w(n, -1) {}int leader(int u){if(w[u] < 0) return u;return w[u] = leader(w[u]);}int operator[](int u){ return leader(u); }int merge(int u, int v){u = leader(u);v = leader(v);if(u == v) return u;if(-w[u] < -w[v]) std::swap(u, v);w[u] += w[v];w[v] = u;return u;}int size(int u){ return -w[leader(u)]; }bool same(int u, int v){ return leader(u) == leader(v); }};} // namespace nachianamespace nachia {class BipartitenessRecognizer {int n;nachia::DsuFast dsu;bool broken;public:BipartitenessRecognizer(int init_n = 0): n(init_n), dsu(n*2), broken(false) {}void addEdge(int u, int v){dsu.merge(u*2, v*2+1);dsu.merge(v*2, u*2+1);if(dsu.same(u*2, u*2+1)) broken = true;}int query(int u, int v){if(dsu.same(u*2,u*2+1) || dsu.same(v*2,v*2+1)) return -2;if(dsu.same(u*2,v*2)) return 0;if(dsu.same(u*2,v*2+1)) return 1;return -1;}};}#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 nachianamespace nachia{struct Graph {public:struct Edge{int from, to;void reverse(){ std::swap(from, to); }int xorval() const { return from ^ to; }};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 nachianamespace nachia{std::vector<int> BfsDistance(const nachia::CsrArray<int>& adj, const std::vector<int>& start){std::vector<int> dist(adj.size(), -1), bfs(adj.size());int p1 = 0;for(int s : start) if(dist[s] == -1){dist[s] = 0;bfs[p1++] = s;}for(int i=0; i<p1; i++){int p = bfs[i];for(int nx : adj[p]) if(dist[nx] == -1){dist[nx] = dist[p] + 1;bfs[p1++] = nx;}}return dist;}} // namespace nachiavoid testcase(){int N,M; cin >> N >> M;int S,T,K; cin >> S >> T >> K; S--; T--;nachia::BipartitenessRecognizer bip(N);auto graph = nachia::Graph::Input(cin, N, true, M, 1);for(auto [u,v] : graph) bip.addEdge(u,v);int q = bip.query(S, T);int dist = nachia::BfsDistance(graph.getAdjacencyArray(), {{S}})[T];if(S == T){if(N == 1 || K % 2 == 1){ cout << "No\n"; return; }for(auto [u,v] : graph) if (u == S || v == S){ cout << "Yes\n"; return; }cout << "Unknown\n";} else if(q != -1 && q != K%2){cout << "No\n";} else if(N == 2){if(K % 2 == 0) cout << "No\n";else if(M != 0) cout << "Yes\n";else cout << "Unknown\n";} else if(q == -1 || dist > K){cout << "Unknown\n";} else {cout << "Yes\n";}}int main(){ios::sync_with_stdio(false); cin.tie(nullptr);#ifdef NACHIAint T; cin >> T; for(int t=0; t<T; T!=++t?(cout<<'\n'),0:0)#endiftestcase();return 0;}