// 入力制約チェック #ifndef INCLUDE_MODE #define INCLUDE_MODE // #define REACTIVE // #define USE_GETLINE #endif #ifdef INCLUDE_MAIN inline void Solve() { static const constexpr PrimeEnumeration pe; CEXPR( int , bound , 1e9 ); CIN_ASSERT( A , 1 , bound ); CIN_ASSERT( B , A , bound ); auto D = EnumerateDivisor( pe , B - A ); sort( D ); int r = D.size() - 1; while( r && D[r-1] >= A ){ r--; } COUT( A < B ? max( D[r] - A , -1 ) : 0 ); } REPEAT_MAIN(1e2); #else // INCLUDE_MAIN #ifdef INCLUDE_LIBRARY // https://github.com/p-adic/cpp // VVV ライブラリは以下に挿入する。 // 圧縮用 #define TE template #define TY typename #define US using #define ST static #define AS assert #define IN inline #define CL class #define PU public #define OP operator #define CE constexpr #define CO const #define NE noexcept #define RE return #define WH while #define VO void #define VE vector #define LI list #define BE begin #define EN end #define SZ size #define LE length #define PW Power #define MO move #define TH this #define CRI CO int& #define CRUI CO uint& #define CRL CO ll& #define VI virtual #define IS basic_istream #define OS basic_ostream #define ST_AS static_assert #define reMO_CO remove_const #define is_COructible_v is_constructible_v #define rBE rbegin #define reSZ resize template void sort( vector& a , const bool& reversed = false ) { if( reversed ){ static auto comp = []( const T& t0 , const T& t1 ) { return t1 < t0; }; sort( a.begin() , a.end() , comp ); } else { sort( a.begin() , a.end() ); } } #ifdef DEBUG #include "c:/Users/user/Documents/Programming/Mathematics/Arithmetic/Prime/Divisor/a_Body.hpp" #else // nの素因数分解:SetPrimeFactorisation(CO PE& prime,CO INT& n,VE& P,VE& EX) // nの約数数え上げ:CountDivisor(CO PE& pe,INT n) // nの約数辞書順列挙1:EnumerateDivisor(CO PE& pe,INT n) // nの約数辞書順列挙2:EnumerateDivisor(CO LD& ld,INT n) // SZ_max未満の数の約数全列挙:TotalEnumerateDivisor(CRI SZ) TE CL PrimeEnumeration{PU:bool m_is_composite[val_limit];INT m_val[LE_max];int m_LE;CE PrimeEnumeration();IN CO INT& OP[](CRI i)CO;CE CO INT& Get(CRI i)CO;CE CO bool& IsComposite(CRI n)CO;CE CRI LE()CO NE;}; TE CE PrimeEnumeration::PrimeEnumeration():m_is_composite(),m_val(),m_LE(0){for(INT i = 2;i < val_limit;i++){if(! m_is_composite[i]){for(INT j = i * i;j < val_limit;j += i){m_is_composite[j]= true;}m_val[m_LE++]= i;if(m_LE >= LE_max){break;}}}}TE IN CO INT& PrimeEnumeration::OP[](CRI i)CO{AS(0 <= i && i < m_LE);RE m_val[i];}TE CE CO INT& PrimeEnumeration::Get(CRI i)CO{RE m_val[i];}TE CE CO bool& PrimeEnumeration::IsComposite(CRI n)CO{RE m_is_composite[n];}TE CE CRI PrimeEnumeration::LE()CO NE{RE m_LE;} TE VO SetPrimeFactorisation(CO PrimeEnumeration& prime,INT1 n,VE& P,VE& EX){int i = 0;WH(i < prime.m_LE){CO INT2& p = prime[i];if(p * p > n){break;}if(n % p == 0){P.push_back(p);EX.push_back(1);INT3& EX_back = EX.back();n /= p;WH(n % p == 0){EX_back++;n /= p;}}i++;}if(n != 1){P.push_back(n);EX.push_back(1);}RE;} TE CL LeastDivisor{PU:INT m_val[val_limit];CE LeastDivisor()NE;IN CO INT& OP[](CRI i)CO;CE CO INT& Get(CRI i)CO;}; TE CE LeastDivisor::LeastDivisor()NE:m_val{}{for(int d = 2;d < val_limit;d++){if(m_val[d]== 0){for(int n = d;n < val_limit;n += d){m_val[n]== 0?m_val[n]= d:d;}}}}TE IN CO INT& LeastDivisor::OP[](CRI i)CO{AS(0 <= i && i < val_limit);RE m_val[i];}TE CE CO INT& LeastDivisor::Get(CRI i)CO{RE m_val[i];} TE INT CountDivisorBody(VE& EX)NE{CO int LE = EX.SZ();INT AN = 1;for(int i = 0;i < LE;i++){AN *= ++EX[i];}RE AN;}TE INT CountDivisor(CO INT& n)NE{VE P{},EX{};SetPrimeFactorisation(n,P,EX);RE CountDivisorBody(EX);}TE INT CountDivisor(CO PE& pe,INT n)NE{VE P{},EX{};SetPrimeFactorisation(pe,n,P,EX);RE CountDivisorBody(EX);}TE VE EnumerateDivisorBody(CO VE& P,VE& EX){CO int LE = P.SZ();VE AN(CountDivisorBody(EX),1);int SZ = 1;for(int i = 0;i < LE;i++){CO INT& P_i = P[i];CRI EX_i = EX[i];INT PW = 1;int j_shift = 0;for(int e = 1;e < EX_i;e++){PW *= P_i;j_shift += SZ;for(int j = 0;j < SZ;j++){AN[j + j_shift]= AN[j]* PW;}}SZ *= EX_i;}RE AN;}TE VE EnumerateDivisor(CO PrimeEnumeration& pe,INT2 n){VE P{},EX{};SetPrimeFactorisation(pe,MO(n),P,EX);RE EnumerateDivisorBody(P,EX);}TE VE EnumerateDivisor(CO LeastDivisor& ld,INT2 n){VE P{},EX{};WH(n > 1){auto& p = ld[n];P.push_back(p);INT2 e = 1;WH((n /= p)% p == 0){e++;}EX.push_back(e);}RE EnumerateDivisorBody(P,EX);}TE VE> TotalEnumerateDivisor(CO INT& SZ)NE{VE> AN(SZ);for(int d = 1;d < SZ;d++){for(int n = 0;n < SZ;n += d){AN[n].push_back(d);}}RE AN;} #endif // AAA ライブラリは以上に挿入する。 #define INCLUDE_MAIN #include __FILE__ #else // INCLUDE_LIBRARY #ifdef DEBUG #define _GLIBCXX_DEBUG #define DEXPR( LL , BOUND , VALUE1 , VALUE2 ) CEXPR( LL , BOUND , VALUE2 ) #define SIGNAL signal( SIGABRT , &AlertAbort ); #define ASSERT( A , MIN , MAX ) CERR( "ASSERTチェック: " , ( MIN ) , ( ( MIN ) <= A ? "<=" : ">" ) , A , ( A <= ( MAX ) ? "<=" : ">" ) , ( MAX ) ); assert( ( MIN ) <= A && A <= ( MAX ) ) #define CERR( ... ) VariadicCout( cerr , __VA_ARGS__ ) << endl #define COUT( ... ) VariadicCout( cout << "出力: " , __VA_ARGS__ ) << endl #define CERR_A( A , N ) OUTPUT_ARRAY( cerr , A , N ) << endl #define COUT_A( A , N ) cout << "出力: "; OUTPUT_ARRAY( cout , A , N ) << endl #define CERR_ITR( A ) OUTPUT_ITR( cerr , A ) << endl #define COUT_ITR( A ) cout << "出力: "; OUTPUT_ITR( cout , A ) << endl #else #pragma GCC optimize ( "O3" ) #pragma GCC optimize ( "unroll-loops" ) #pragma GCC target ( "sse4.2,fma,avx2,popcnt,lzcnt,bmi2" ) #define SIGNAL #define DEXPR( LL , BOUND , VALUE1 , VALUE2 ) CEXPR( LL , BOUND , VALUE1 ) #define ASSERT( A , MIN , MAX ) assert( ( MIN ) <= A && A <= ( MAX ) ) #define CERR( ... ) #define COUT( ... ) VariadicCout( cout , __VA_ARGS__ ) << ENDL #define CERR_A( N , A ) #define COUT_A( N , A ) OUTPUT_ARRAY( cout , N , A ) << ENDL #define CERR_ITR( A ) #define COUT_ITR( A ) OUTPUT_ITR( cout , A ) << ENDL #endif #ifdef REACTIVE #define ENDL endl #else #define ENDL "\n" #endif #ifdef USE_GETLINE #define SET_LL( A ) { GETLINE( A ## _str ); A = stoll( A ## _str ); } #define GETLINE_SEPARATE( SEPARATOR , ... ) string __VA_ARGS__; VariadicGetline( cin , SEPARATOR , __VA_ARGS__ ) #define GETLINE( ... ) GETLINE_SEPARATE( '\n' , __VA_ARGS__ ) #else #define SET_LL( A ) cin >> A #define CIN( LL , ... ) LL __VA_ARGS__; VariadicCin( cin , __VA_ARGS__ ) #define SET_A( N , ... ) VariadicResize( N , __VA_ARGS__ ); FOR( VARIABLE_FOR_SET_A , 0 , N ){ VariadicSet( cin , VARIABLE_FOR_SET_A , __VA_ARGS__ ); } #define CIN_A( LL , N , ... ) VE __VA_ARGS__; SET_A( N , __VA_ARGS__ ); #endif #include using namespace std; #define REPEAT_MAIN( BOUND ) int main(){ ios_base::sync_with_stdio( false ); cin.tie( nullptr ); SIGNAL; CEXPR( int , bound_test_case_num , BOUND ); int test_case_num = 1; if constexpr( bound_test_case_num > 1 ){ CERR( "テストケースの個数を入力してください。" ); SET_ASSERT( test_case_num , 1 , bound_test_case_num ); } REPEAT( test_case_num ){ if constexpr( bound_test_case_num > 1 ){ CERR( "testcase " , VARIABLE_FOR_REPEAT_test_case_num , ":" ); } Solve(); CERR( "" ); } CHECK_REDUNDANT_INPUT; } #define START_WATCH chrono::system_clock::time_point watch = chrono::system_clock::now() #define CURRENT_TIME static_cast( chrono::duration_cast( chrono::system_clock::now() - watch ).count() / 1000.0 ) #define CHECK_WATCH( TL_MS ) ( CURRENT_TIME < TL_MS - 100.0 ) #define CEXPR( LL , BOUND , VALUE ) constexpr LL BOUND = VALUE #define SET_ASSERT( A , MIN , MAX ) SET_LL( A ); ASSERT( A , MIN , MAX ) #define SET_A_ASSERT( N , A , MIN , MAX ) FOR( VARIABLE_FOR_SET_A , 0 , N ){ SET_ASSERT( A[VARIABLE_FOR_SET_A] , MIN , MAX ); } #define CIN_ASSERT( A , MIN , MAX ) decldecay_t( MAX ) A; SET_ASSERT( A , MIN , MAX ) #define CIN_A_ASSERT( N , A , MIN , MAX ) vector A( N ); SET_A_ASSERT( N , A , MIN , MAX ) #define FOR( VAR , INITIAL , FINAL_PLUS_ONE ) for( decldecay_t( FINAL_PLUS_ONE ) VAR = INITIAL ; VAR < FINAL_PLUS_ONE ; VAR ++ ) #define FOREQ( VAR , INITIAL , FINAL ) for( decldecay_t( FINAL ) VAR = INITIAL ; VAR <= FINAL ; VAR ++ ) #define FOREQINV( VAR , INITIAL , FINAL ) for( decldecay_t( INITIAL ) VAR = INITIAL ; VAR + 1 > FINAL ; VAR -- ) #define ITR( ARRAY ) auto begin_ ## ARRAY = ARRAY .BE() , itr_ ## ARRAY = begin_ ## ARRAY , end_ ## ARRAY = ARRAY .EN() #define FOR_ITR( ARRAY ) for( ITR( ARRAY ) , itr = itr_ ## ARRAY ; itr_ ## ARRAY != end_ ## ARRAY ; itr_ ## ARRAY ++ , itr++ ) #define RUN( VAR , ARRAY ) for( auto&& VAR : ARRAY ) #define REPEAT( HOW_MANY_TIMES ) FOR( VARIABLE_FOR_REPEAT_ ## HOW_MANY_TIMES , 0 , HOW_MANY_TIMES ) #define SET_PRECISION( DECIMAL_DIGITS ) cout << fixed << setprecision( DECIMAL_DIGITS ) #define RETURN( ... ) COUT( __VA_ARGS__ ); return // 型のエイリアス #define decldecay_t( VAR ) decay_t template using ret_t = decltype( declval()( declval()... ) ); template using inner_t = typename T::type; using uint = unsigned int; using ll = long long; using ull = unsigned long long; using ld = long double; using lld = __float128; template using T2 = pair; template using T3 = tuple; template using T4 = tuple; using path = pair; // 入出力用 template typename V> inline auto operator>>( basic_istream& is , V& arg ) -> decltype((get<0>(arg),is))& { return is >> get<0>( arg ) >> get<1>( arg ); } template inline basic_istream& operator>>( basic_istream& is , tuple& arg ) { return is >> get<0>( arg ) >> get<1>( arg ) >> get<2>( arg ); } template inline basic_istream& operator>>( basic_istream& is , tuple& arg ) { return is >> get<0>( arg ) >> get<1>( arg ) >> get<2>( arg ) >> get<3>( arg ); } template typename V> inline auto operator<<( basic_ostream& os , const V& arg ) -> decltype((get<0>(arg),os))& { return os << get<0>( arg ) << " " << get<1>( arg ); } template inline basic_ostream& operator<<( basic_ostream& os , const tuple& arg ) { return os << get<0>( arg ) << " " << get<1>( arg ) << " " << get<2>( arg ); } template inline basic_ostream& operator<<( basic_ostream& os , const tuple& arg ) { return os << get<0>( arg ) << " " << get<1>( arg ) << " " << get<2>( arg ) << " " << get<3>( arg ); } #define DEFINITION_OF_COUT_FOR_VECTOR( V ) template inline basic_ostream& operator<<( basic_ostream& os , const V& arg ) { auto begin = arg.begin() , end = arg.end(); auto itr = begin; while( itr != end ){ ( itr == begin ? os : os << " " ) << *itr; itr++; } return os; } DEFINITION_OF_COUT_FOR_VECTOR( vector ); DEFINITION_OF_COUT_FOR_VECTOR( list ); DEFINITION_OF_COUT_FOR_VECTOR( set ); DEFINITION_OF_COUT_FOR_VECTOR( unordered_set ); inline void VariadicResize( const int& size ) {} template inline void VariadicResize( const int& size , Arg& arg , ARGS&... args ) { arg.resize( size ); VariadicResize( size , args... ); } template inline basic_istream& VariadicCin( basic_istream& is ) { return is; } template inline basic_istream& VariadicCin( basic_istream& is , Arg& arg , ARGS&... args ) { return VariadicCin( is >> arg , args... ); } template inline basic_istream& VariadicSet( basic_istream& is , const int& i ) { return is; } template inline basic_istream& VariadicSet( basic_istream& is , const int& i , Arg& arg , ARGS&... args ) { return VariadicSet( is >> arg[i] , i , args... ); } template inline basic_istream& VariadicGetline( basic_istream& is , const char& separator ) { return is; } template inline basic_istream& VariadicGetline( basic_istream& is , const char& separator , Arg& arg , ARGS&... args ) { return VariadicGetline( getline( is , arg , separator ) , separator , args... ); } template inline basic_ostream& VariadicCout( basic_ostream& os , const Arg& arg ) { return os << arg; } template inline basic_ostream& VariadicCout( basic_ostream& os , const Arg1& arg1 , const Arg2& arg2 , const ARGS&... args ) { return VariadicCout( os << arg1 << " " , arg2 , args... ); } // デバッグ用 #ifdef DEBUG inline void AlertAbort( int n ) { CERR( "abort関数が呼ばれました。assertマクロのメッセージが出力されていない場合はオーバーフローの有無を確認をしてください。" ); } #endif // 入力フォーマットチェック用 // 1行中の変数の個数をSEPARATOR区切りで確認 #define GETLINE_COUNT( S , VARIABLE_NUMBER , SEPARATOR ) GETLINE( S ); int VARIABLE_FOR_INDEX_FOR_GETLINE_FOR_ ## S = 0; int VARIABLE_FOR_SIZE_FOR_GETLINE_FOR_ ## S = S.size(); { int size = S.size(); int count = 0; for( int i = 0 ; i < size ; i++ ){ if( S.substr( i , 1 ) == SEPARATOR ){ count++; } } assert( count + 1 == VARIABLE_NUMBER ); } // 余計な入力の有無を確認 #ifdef DEBUG #define CHECK_REDUNDANT_INPUT #else #ifdef USE_GETLINE #define CHECK_REDUNDANT_INPUT string VARIABLE_FOR_CHECK_REDUNDANT_INPUT = ""; getline( cin , VARIABLE_FOR_CHECK_REDUNDANT_INPUT ); assert( VARIABLE_FOR_CHECK_REDUNDANT_INPUT == "" ); assert( ! cin ) #else #define CHECK_REDUNDANT_INPUT string VARIABLE_FOR_CHECK_REDUNDANT_INPUT = ""; cin >> VARIABLE_FOR_CHECK_REDUNDANT_INPUT; assert( VARIABLE_FOR_CHECK_REDUNDANT_INPUT == "" ); assert( ! cin ) #endif #endif // |N| <= BOUNDを満たすNをSから構築 #define STOI( S , N , BOUND ) decldecay_t( BOUND ) N = 0; { bool VARIABLE_FOR_POSITIVITY_FOR_GETLINE = true; assert( VARIABLE_FOR_INDEX_FOR_GETLINE_FOR_ ## S < VARIABLE_FOR_SIZE_FOR_GETLINE_FOR_ ## S ); if( S.substr( VARIABLE_FOR_INDEX_FOR_GETLINE_FOR_ ## S , 1 ) == "-" ){ VARIABLE_FOR_POSITIVITY_FOR_GETLINE = false; VARIABLE_FOR_INDEX_FOR_GETLINE_FOR_ ## S ++; assert( VARIABLE_FOR_INDEX_FOR_GETLINE_FOR_ ## S < VARIABLE_FOR_SIZE_FOR_GETLINE_FOR_ ## S ); } assert( S.substr( VARIABLE_FOR_INDEX_FOR_GETLINE_FOR_ ## S , 1 ) != " " ); string VARIABLE_FOR_LETTER_FOR_GETLINE{}; int VARIABLE_FOR_DIGIT_FOR_GETLINE{}; while( VARIABLE_FOR_INDEX_FOR_GETLINE_FOR_ ## S < VARIABLE_FOR_SIZE_FOR_GETLINE_FOR_ ## S ? ( VARIABLE_FOR_LETTER_FOR_GETLINE = S.substr( VARIABLE_FOR_INDEX_FOR_GETLINE_FOR_ ## S , 1 ) ) != " " : false ){ VARIABLE_FOR_DIGIT_FOR_GETLINE = stoi( VARIABLE_FOR_LETTER_FOR_GETLINE ); assert( N < BOUND / 10 ? true : N == BOUND / 10 && VARIABLE_FOR_DIGIT_FOR_GETLINE <= BOUND % 10 ); N = N * 10 + VARIABLE_FOR_DIGIT_FOR_GETLINE; VARIABLE_FOR_INDEX_FOR_GETLINE_FOR_ ## S ++; } if( ! VARIABLE_FOR_POSITIVITY_FOR_GETLINE ){ N *= -1; } if( VARIABLE_FOR_INDEX_FOR_GETLINE_FOR_ ## S < VARIABLE_FOR_SIZE_FOR_GETLINE_FOR_ ## S ){ VARIABLE_FOR_INDEX_FOR_GETLINE_FOR_ ## S ++; } } #define STOI_A( S , N , A , BOUND ) vector A( N ); FOR( VARIABLE_FOR_STOI_A , 0 , N ){ STOI( S , A ##_VARIABLE_FOR_STOI_A , BOUND ); A[VARIABLE_FOR_STOI_A] = A ##_VARIABLE_FOR_STOI_A; } // SをSEPARATORで区切りTを構築 #define SEPARATE( S , T , SEPARATOR ) string T{}; { assert( VARIABLE_FOR_INDEX_FOR_GETLINE_FOR_ ## S < VARIABLE_FOR_SIZE_FOR_GETLINE_FOR_ ## S ); int VARIABLE_FOR_INDEX_FOR_GETLINE_FOR_ ## S_prev = VARIABLE_FOR_INDEX_FOR_GETLINE_FOR_ ## S; assert( S.substr( VARIABLE_FOR_INDEX_FOR_GETLINE_FOR_ ## S , 1 ) != SEPARATOR ); string VARIABLE_FOR_LETTER_FOR_GETLINE{}; while( VARIABLE_FOR_INDEX_FOR_GETLINE_FOR_ ## S < VARIABLE_FOR_SIZE_FOR_GETLINE_FOR_ ## S ? ( VARIABLE_FOR_LETTER_FOR_GETLINE = S.substr( VARIABLE_FOR_INDEX_FOR_GETLINE_FOR_ ## S , 1 ) ) != SEPARATOR : false ){ VARIABLE_FOR_INDEX_FOR_GETLINE_FOR_ ## S ++; } T = S.substr( VARIABLE_FOR_INDEX_FOR_GETLINE_FOR_ ## S_prev , VARIABLE_FOR_INDEX_FOR_GETLINE_FOR_ ## S - VARIABLE_FOR_INDEX_FOR_GETLINE_FOR_ ## S_prev ); if( VARIABLE_FOR_INDEX_FOR_GETLINE_FOR_ ## S < VARIABLE_FOR_SIZE_FOR_GETLINE_FOR_ ## S ){ VARIABLE_FOR_INDEX_FOR_GETLINE_FOR_ ## S ++; } } #define INCLUDE_LIBRARY #include __FILE__ #endif // INCLUDE_LIBRARY #endif // INCLUDE_MAIN