結果
問題 | No.1976 Cut then Connect |
ユーザー |
👑 ![]() |
提出日時 | 2023-02-19 05:21:27 |
言語 | C++17 (gcc 13.3.0 + boost 1.87.0) |
結果 |
WA
|
実行時間 | - |
コード長 | 13,909 bytes |
コンパイル時間 | 1,132 ms |
コンパイル使用メモリ | 88,216 KB |
最終ジャッジ日時 | 2025-02-10 19:03:11 |
ジャッジサーバーID (参考情報) |
judge5 / judge3 |
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ファイルパターン | 結果 |
---|---|
sample | AC * 1 WA * 1 |
other | AC * 28 WA * 3 |
ソースコード
#line 2 "nachia\\graph\\graph.hpp"#include <vector>#include <utility>#include <cassert>#line 4 "nachia\\array\\csr-array.hpp"#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 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(std::move(edges)), m_isUndir(undirected) {}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]; }}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 5 "nachia\\tree\\any-direction-tree-dp.hpp"namespace nachia{struct S {int height = 0;int diam = 0;};S rake(S l, S r){S res;res.height = std::max(l.height, r.height);res.diam = std::max({ l.diam, r.diam, l.height + r.height });return res;}S compress(S l, int egdeIdx, int nodeIdx){S res;res.height = l.height + 1;res.diam = std::max(l.diam, res.height);return res;}struct AnyDirectionTreeDP{std::vector<S> low;std::vector<S> high;std::vector<int> XorEdge;std::vector<int> P;AnyDirectionTreeDP(const Graph& tree, std::vector<S> node){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 = {0};bfs.reserve(n);P.assign(n, -1);for(int i=0; i<n; i++){int v = bfs[i];for(int e : adj[v]){int w = v ^ XorEdge[e];if(P[v] != e){ P[w] = e; bfs.push_back(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[v], v));}high = node;for(int i=0; i<n; i++){int v = bfs[i];int C = adj[v].size();S fold = high[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(fold, compress(low[w], e, v));}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] = compress(rake(high[w], fold), e, w);fold = rake(fold, compress(low[w], e, v));}}}S getAtVtx(int i){ return rake(high[i], low[i]); }S getAtEdge(int from, int edge){if(P[from] == edge) return high[from ^ XorEdge[edge]];return low[from];}};} // namespace nachia#line 2 "nachia\\misc\\fastio.hpp"#include <cstdio>#include <cctype>#include <cstdint>#include <string>namespace nachia{struct CInStream{private:static const unsigned int INPUT_BUF_SIZE = 1 << 17;unsigned int p = INPUT_BUF_SIZE;static char Q[INPUT_BUF_SIZE];public:using MyType = CInStream;char seekChar() noexcept {if(p == INPUT_BUF_SIZE){size_t len = fread(Q, 1, INPUT_BUF_SIZE, stdin);if(len != INPUT_BUF_SIZE) Q[len] = '\0';p = 0;}return Q[p];}void skipSpace() noexcept { while(isspace(seekChar())) p++; }uint32_t nextU32() noexcept {skipSpace();uint32_t buf = 0;while(true){char tmp = seekChar();if('9' < tmp || tmp < '0') break;buf = buf * 10 + (tmp - '0');p++;}return buf;}int32_t nextI32() noexcept {skipSpace();if(seekChar() == '-'){ p++; return (int32_t)(-nextU32()); }return (int32_t)nextU32();}uint64_t nextU64() noexcept {skipSpace();uint64_t buf = 0;while(true){char tmp = seekChar();if('9' < tmp || tmp < '0') break;buf = buf * 10 + (tmp - '0');p++;}return buf;}int64_t nextI64() noexcept {skipSpace();if(seekChar() == '-'){ p++; return (int64_t)(-nextU64()); }return (int64_t)nextU64();}char nextChar() noexcept { skipSpace(); char buf = seekChar(); p++; return buf; }std::string nextToken(){skipSpace();std::string buf;while(true){char ch = seekChar();if(isspace(ch) || ch == '\0') break;buf.push_back(ch);p++;}return buf;}MyType& operator>>(unsigned int& dest) noexcept { dest = nextU32(); return *this; }MyType& operator>>(int& dest) noexcept { dest = nextI32(); return *this; }MyType& operator>>(unsigned long& dest) noexcept { dest = nextU64(); return *this; }MyType& operator>>(long& dest) noexcept { dest = nextI64(); return *this; }MyType& operator>>(unsigned long long& dest) noexcept { dest = nextU64(); return *this; }MyType& operator>>(long long& dest) noexcept { dest = nextI64(); return *this; }MyType& operator>>(std::string& dest){ dest = nextToken(); return *this; }MyType& operator>>(char& dest) noexcept { dest = nextChar(); return *this; }} cin;struct FastOutputTable{char LZ[1000][4] = {};char NLZ[1000][4] = {};constexpr FastOutputTable(){using u32 = uint_fast32_t;for(u32 d=0; d<1000; d++){LZ[d][0] = ('0' + d / 100 % 10);LZ[d][1] = ('0' + d / 10 % 10);LZ[d][2] = ('0' + d / 1 % 10);LZ[d][3] = '\0';}for(u32 d=0; d<1000; d++){u32 i = 0;if(d >= 100) NLZ[d][i++] = ('0' + d / 100 % 10);if(d >= 10) NLZ[d][i++] = ('0' + d / 10 % 10);if(d >= 1) NLZ[d][i++] = ('0' + d / 1 % 10);NLZ[d][i++] = '\0';}}};struct COutStream{private:using u32 = uint32_t;using u64 = uint64_t;using MyType = COutStream;static const u32 OUTPUT_BUF_SIZE = 1 << 17;static char Q[OUTPUT_BUF_SIZE];static constexpr FastOutputTable TB = FastOutputTable();u32 p = 0;static constexpr u32 P10(u32 d){ return d ? P10(d-1)*10 : 1; }static constexpr u64 P10L(u32 d){ return d ? P10L(d-1)*10 : 1; }template<class T, class U> static void Fil(T& m, U& l, U x) noexcept { m = l/x; l -= m*x; }void next_dig9(u32 x){u32 y;Fil(y, x, P10(6));nextCstr(TB.LZ[y]);Fil(y, x, P10(3));nextCstr(TB.LZ[y]); nextCstr(TB.LZ[x]);}public:void nextChar(char c){Q[p++] = c;if(p == OUTPUT_BUF_SIZE){ fwrite(Q, p, 1, stdout); p = 0; }}void nextEoln(){ nextChar('\n'); }void nextCstr(const char* s){ while(*s) nextChar(*(s++)); }void nextU32(uint32_t x){u32 y = 0;if(x >= P10(9)){Fil(y, x, P10(9));nextCstr(TB.NLZ[y]); next_dig9(x);}else if(x >= P10(6)){Fil(y, x, P10(6));nextCstr(TB.NLZ[y]);Fil(y, x, P10(3));nextCstr(TB.LZ[y]); nextCstr(TB.LZ[x]);}else if(x >= P10(3)){Fil(y, x, P10(3));nextCstr(TB.NLZ[y]); nextCstr(TB.LZ[x]);}else if(x >= 1) nextCstr(TB.NLZ[x]);else nextChar('0');}void nextI32(int32_t x){if(x >= 0) nextU32(x);else{ nextChar('-'); nextU32((u32)-x); }}void nextU64(uint64_t x){u32 y = 0;if(x >= P10L(18)){Fil(y, x, P10L(18));nextU32(y);Fil(y, x, P10L(9));next_dig9(y); next_dig9(x);}else if(x >= P10L(9)){Fil(y, x, P10L(9));nextU32(y); next_dig9(x);}else nextU32(x);}void nextI64(int64_t x){if(x >= 0) nextU64(x);else{ nextChar('-'); nextU64((u64)-x); }}void writeToFile(bool flush = false){fwrite(Q, p, 1, stdout);if(flush) fflush(stdout);p = 0;}COutStream(){ Q[0] = 0; }~COutStream(){ writeToFile(); }MyType& operator<<(unsigned int tg){ nextU32(tg); return *this; }MyType& operator<<(unsigned long tg){ nextU64(tg); return *this; }MyType& operator<<(unsigned long long tg){ nextU64(tg); return *this; }MyType& operator<<(int tg){ nextI32(tg); return *this; }MyType& operator<<(long tg){ nextI64(tg); return *this; }MyType& operator<<(long long tg){ nextI64(tg); return *this; }MyType& operator<<(const std::string& tg){ nextCstr(tg.c_str()); return *this; }MyType& operator<<(const char* tg){ nextCstr(tg); return *this; }MyType& operator<<(char tg){ nextChar(tg); return *this; }} cout;char CInStream::Q[INPUT_BUF_SIZE];char COutStream::Q[OUTPUT_BUF_SIZE];} // namespace nachia#line 4 "Main.cpp"int main(){using nachia::cin, nachia::cout;int N; cin >> N;nachia::Graph tree(N, true);for(int i=0; i<N-1; i++){int u, v; cin >> u >> v; u--; v--;tree.addEdge(u, v);}auto treedp = nachia::AnyDirectionTreeDP(tree, std::vector<nachia::S>(N));int ans = N;for(int e=0; e<N-1; e++){int diam1 = treedp.getAtEdge(tree[e].from, e).diam;int diam2 = treedp.getAtEdge(tree[e].to, e).diam;int cr_ans = (diam1 + 1) / 2 + (diam2 + 1) / 2 + 1;cr_ans = std::max({ cr_ans, diam1, diam2 });ans = std::min(ans, cr_ans);}cout << ans << '\n';return 0;}