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#include "string/lcp-array.hpp"
#include "suffix-array.hpp" /** * @brief LCP Array */ template< typename T > vector< int > lcp_array(const SuffixArray< T > &sa) { int n = (int) sa.size() - 1; vector< int > lcp(n + 1), rank(n + 1); for(int i = 0; i <= n; i++) { rank[sa[i]] = i; } int h = 0; for(int i = 0; i <= n; i++) { if(rank[i] < n) { int j = sa[rank[i] + 1]; for(; j + h < n && i + h < n; h++) { if(sa.vs[j + h] != sa.vs[i + h]) break; } lcp[rank[i] + 1] = h; if(h > 0) h--; } } return lcp; }
#line 1 "string/suffix-array.hpp" /** * @brief Suffix Array(接尾辞配列) */ template< typename T > struct SuffixArray : vector< int > { private: vector< int > sa_is(const vector< int > &s) const { const int n = (int) s.size(); vector< int > ret(n); vector< int > is_s(n), is_lms(n); int m = 0; for(int i = n - 2; i >= 0; i--) { is_s[i] = (s[i] > s[i + 1]) or (s[i] == s[i + 1] and is_s[i + 1]); m += (is_lms[i + 1] = is_s[i] and not is_s[i + 1]); } auto induced_sort = [&](const vector< int > &lms) { int upper = *max_element(s.begin(), s.end()); vector< int > l(upper + 2), r(upper + 2); for(auto &&v: s) { ++l[v + 1]; ++r[v]; } partial_sum(l.begin(), l.end(), l.begin()); partial_sum(r.begin(), r.end(), r.begin()); fill(ret.begin(), ret.end(), -1); for(int i = (int) lms.size() - 1; i >= 0; i--) { ret[--r[s[lms[i]]]] = lms[i]; } for(auto &&v: ret) { if(v >= 1 and is_s[v - 1]) ret[l[s[v - 1]]++] = v - 1; } fill(r.begin(), r.end(), 0); for(auto &&v: s) ++r[v]; partial_sum(r.begin(), r.end(), r.begin()); for(int k = (int) ret.size() - 1, i = ret[k]; k >= 1; i = ret[--k]) { if(i >= 1 and not is_s[i - 1]) { ret[--r[s[i - 1]]] = i - 1; } } }; vector< int > lms; lms.reserve(m); for(int i = 1; i < n; i++) { if(is_lms[i]) lms.push_back(i); } induced_sort(lms); vector< int > new_lms; new_lms.reserve(m); for(int i = 0; i < n; i++) { if(not is_s[ret[i]] and ret[i] > 0 and is_s[ret[i] - 1]) { new_lms.push_back(ret[i]); } } auto is_same = [&](int a, int b) { if(s[a++] != s[b++]) return false; for(;; ++a, ++b) { if(s[a] != s[b]) return false; if(is_lms[a] or is_lms[b]) return is_lms[a] and is_lms[b]; } }; int rank = 0; ret[n - 1] = 0; for(int i = 1; i < m; i++) { if(not is_same(new_lms[i - 1], new_lms[i])) ++rank; ret[new_lms[i]] = rank; } if(rank + 1 < m) { vector< int > new_s(m); for(int i = 0; i < m; i++) { new_s[i] = ret[lms[i]]; } auto lms_sa = sa_is(new_s); for(int i = 0; i < m; i++) { new_lms[i] = lms[lms_sa[i]]; } } induced_sort(new_lms); return ret; } public: T vs; explicit SuffixArray(const T &vs, bool compress = false) : vs(vs) { vector< int > new_vs(vs.size() + 1); if(compress) { T xs = vs; sort(xs.begin(), xs.end()); xs.erase(unique(xs.begin(), xs.end()), xs.end()); for(int i = 0; i < (int) vs.size(); i++) { new_vs[i] = std::lower_bound(xs.begin(), xs.end(), vs[i]) - xs.begin() + 1; } } else { auto d = *min_element(vs.begin(), vs.end()); for(int i = 0; i < (int) vs.size(); i++) { new_vs[i] = vs[i] - d + 1; } } auto ret = sa_is(new_vs); assign(ret.begin(), ret.end()); } void output() const { for(int i = 0; i < size(); i++) { cout << i << ":[" << (*this)[i] << "]"; for(int j = (*this)[i]; j < (int) vs.size(); j++) cout << " " << vs[j]; cout << "\n"; } } bool lt_substr(const string &t, int si = 0, int ti = 0) { int sn = (int) vs.size(), tn = (int) t.size(); while(si < sn && ti < tn) { if(vs[si] < t[ti]) return true; if(vs[si] > t[ti]) return false; ++si, ++ti; } return si >= sn && ti < tn; } // t <= s[i,N) なる最小の i を返す O(|t| log |s|) int lower_bound(const T &t) { int ng = 0, ok = (int) size(); while(ok - ng > 1) { int mid = (ok + ng) / 2; if(lt_substr(t, at(mid))) ng = mid; else ok = mid; } return ok; } // O(|t| log |s|) pair< int, int > equal_range(T &t) { int low = lower_bound(t); int ng = low - 1, ok = (int) size(); t.back()++; while(ok - ng > 1) { int mid = (ok + ng) / 2; if(lt_substr(t, at(mid))) ng = mid; else ok = mid; } t.back()--; return {low, ok}; } }; template<> void SuffixArray< string >::output() const { for(int i = 0; i < (int) size(); i++) { cout << i << ":[" << (*this)[i] << "] " << vs.substr((*this)[i]) << "\n"; } } #line 2 "string/lcp-array.hpp" /** * @brief LCP Array */ template< typename T > vector< int > lcp_array(const SuffixArray< T > &sa) { int n = (int) sa.size() - 1; vector< int > lcp(n + 1), rank(n + 1); for(int i = 0; i <= n; i++) { rank[sa[i]] = i; } int h = 0; for(int i = 0; i <= n; i++) { if(rank[i] < n) { int j = sa[rank[i] + 1]; for(; j + h < n && i + h < n; h++) { if(sa.vs[j + h] != sa.vs[i + h]) break; } lcp[rank[i] + 1] = h; if(h > 0) h--; } } return lcp; }