#line 2 "cpplib/util/template.hpp" #pragma GCC optimize("Ofast") #pragma GCC optimize("unroll-loops") #pragma GCC target("avx2") #include using namespace std; struct __INIT__{__INIT__(){cin.tie(0);ios::sync_with_stdio(false);cout< vec; typedef vector> mat; typedef vector>> mat3; typedef vector svec; typedef vector> smat; templateusing V=vector; templateusing VV=V>; templateinline void output(T t){bool f=0;for(auto i:t){cout<<(f?" ":"")<inline void output2(T t){for(auto i:t)output(i);} templateinline void debug(T t){bool f=0;for(auto i:t){cerr<<(f?" ":"")<inline void debug2(T t){for(auto i:t)debug(i);} #define loop(n) for(long long _=0;_<(long long)(n);++_) #define _overload4(_1,_2,_3,_4,name,...) name #define __rep(i,a) repi(i,0,a,1) #define _rep(i,a,b) repi(i,a,b,1) #define repi(i,a,b,c) for(long long i=(long long)(a);i<(long long)(b);i+=c) #define rep(...) _overload4(__VA_ARGS__,repi,_rep,__rep)(__VA_ARGS__) #define _overload3_rev(_1,_2,_3,name,...) name #define _rep_rev(i,a) repi_rev(i,0,a) #define repi_rev(i,a,b) for(long long i=(long long)(b)-1;i>=(long long)(a);--i) #define rrep(...) _overload3_rev(__VA_ARGS__,repi_rev,_rep_rev)(__VA_ARGS__) // #define rep(i,...) for(auto i:range(__VA_ARGS__)) // #define rrep(i,...) for(auto i:reversed(range(__VA_ARGS__))) // #define repi(i,a,b) for(lint i=lint(a);i<(lint)(b);++i) // #define rrepi(i,a,b) for(lint i=lint(b)-1;i>=lint(a);--i) // #define irep(i) for(lint i=0;;++i) // inline vector range(long long n){if(n<=0)return vector();vectorv(n);iota(v.begin(),v.end(),0LL);return v;} // inline vector range(long long a,long long b){if(b<=a)return vector();vectorv(b-a);iota(v.begin(),v.end(),a);return v;} // inline vector range(long long a,long long b,long long c){if((b-a+c-1)/c<=0)return vector();vectorv((b-a+c-1)/c);for(int i=0;i<(int)v.size();++i)v[i]=i?v[i-1]+c:a;return v;} // templateinline T reversed(T v){reverse(v.begin(),v.end());return v;} #define all(n) begin(n),end(n) templatebool chmin(T& s,const E& t){bool res=s>t;s=min(s,t);return res;} templatebool chmax(T& s,const E& t){bool res=s(s,t);return res;} const vector dx={1,0,-1,0,1,1,-1,-1}; const vector dy={0,1,0,-1,1,-1,1,-1}; #define SUM(v) accumulate(all(v),0LL) templateauto make_vector(T x,int arg,Args ...args){if constexpr(sizeof...(args)==0)return vector(arg,x);else return vector(arg,make_vector(x,args...));} #define extrep(v,...) for(auto v:__MAKE_MAT__({__VA_ARGS__})) #define bit(n,a) ((n>>a)&1) vector> __MAKE_MAT__(vector v){if(v.empty())return vector>(1,vector());long long n=v.back();v.pop_back();vector> ret;vector> tmp=__MAKE_MAT__(v);for(auto e:tmp)for(long long i=0;i>; templateusing graph_w=vector>>; templateostream& operator<<(ostream& out,pairv){out<<"("< #ifdef _MSC_VER #include #endif namespace atcoder { namespace internal { // @param m `1 <= m` // @return x mod m constexpr long long safe_mod(long long x, long long m) { x %= m; if (x < 0) x += m; return x; } // Fast modular multiplication by barrett reduction // Reference: https://en.wikipedia.org/wiki/Barrett_reduction // NOTE: reconsider after Ice Lake struct barrett { unsigned int _m; unsigned long long im; // @param m `1 <= m < 2^31` barrett(unsigned int m) : _m(m), im((unsigned long long)(-1) / m + 1) {} // @return m unsigned int umod() const { return _m; } // @param a `0 <= a < m` // @param b `0 <= b < m` // @return `a * b % m` unsigned int mul(unsigned int a, unsigned int b) const { // [1] m = 1 // a = b = im = 0, so okay // [2] m >= 2 // im = ceil(2^64 / m) // -> im * m = 2^64 + r (0 <= r < m) // let z = a*b = c*m + d (0 <= c, d < m) // a*b * im = (c*m + d) * im = c*(im*m) + d*im = c*2^64 + c*r + d*im // c*r + d*im < m * m + m * im < m * m + 2^64 + m <= 2^64 + m * (m + 1) < 2^64 * 2 // ((ab * im) >> 64) == c or c + 1 unsigned long long z = a; z *= b; #ifdef _MSC_VER unsigned long long x; _umul128(z, im, &x); #else unsigned long long x = (unsigned long long)(((unsigned __int128)(z)*im) >> 64); #endif unsigned int v = (unsigned int)(z - x * _m); if (_m <= v) v += _m; return v; } }; // @param n `0 <= n` // @param m `1 <= m` // @return `(x ** n) % m` constexpr long long pow_mod_constexpr(long long x, long long n, int m) { if (m == 1) return 0; unsigned int _m = (unsigned int)(m); unsigned long long r = 1; unsigned long long y = safe_mod(x, m); while (n) { if (n & 1) r = (r * y) % _m; y = (y * y) % _m; n >>= 1; } return r; } // Reference: // M. Forisek and J. Jancina, // Fast Primality Testing for Integers That Fit into a Machine Word // @param n `0 <= n` constexpr bool is_prime_constexpr(int n) { if (n <= 1) return false; if (n == 2 || n == 7 || n == 61) return true; if (n % 2 == 0) return false; long long d = n - 1; while (d % 2 == 0) d /= 2; constexpr long long bases[3] = {2, 7, 61}; for (long long a : bases) { long long t = d; long long y = pow_mod_constexpr(a, t, n); while (t != n - 1 && y != 1 && y != n - 1) { y = y * y % n; t <<= 1; } if (y != n - 1 && t % 2 == 0) { return false; } } return true; } template constexpr bool is_prime = is_prime_constexpr(n); // @param b `1 <= b` // @return pair(g, x) s.t. g = gcd(a, b), xa = g (mod b), 0 <= x < b/g constexpr std::pair inv_gcd(long long a, long long b) { a = safe_mod(a, b); if (a == 0) return {b, 0}; // Contracts: // [1] s - m0 * a = 0 (mod b) // [2] t - m1 * a = 0 (mod b) // [3] s * |m1| + t * |m0| <= b long long s = b, t = a; long long m0 = 0, m1 = 1; while (t) { long long u = s / t; s -= t * u; m0 -= m1 * u; // |m1 * u| <= |m1| * s <= b // [3]: // (s - t * u) * |m1| + t * |m0 - m1 * u| // <= s * |m1| - t * u * |m1| + t * (|m0| + |m1| * u) // = s * |m1| + t * |m0| <= b auto tmp = s; s = t; t = tmp; tmp = m0; m0 = m1; m1 = tmp; } // by [3]: |m0| <= b/g // by g != b: |m0| < b/g if (m0 < 0) m0 += b / s; return {s, m0}; } // Compile time primitive root // @param m must be prime // @return primitive root (and minimum in now) constexpr int primitive_root_constexpr(int m) { if (m == 2) return 1; if (m == 167772161) return 3; if (m == 469762049) return 3; if (m == 754974721) return 11; if (m == 998244353) return 3; int divs[20] = {}; divs[0] = 2; int cnt = 1; int x = (m - 1) / 2; while (x % 2 == 0) x /= 2; for (int i = 3; (long long)(i)*i <= x; i += 2) { if (x % i == 0) { divs[cnt++] = i; while (x % i == 0) { x /= i; } } } if (x > 1) { divs[cnt++] = x; } for (int g = 2;; g++) { bool ok = true; for (int i = 0; i < cnt; i++) { if (pow_mod_constexpr(g, (m - 1) / divs[i], m) == 1) { ok = false; break; } } if (ok) return g; } } template constexpr int primitive_root = primitive_root_constexpr(m); } // namespace internal } // namespace atcoder #include #include #include namespace atcoder { namespace internal { #ifndef _MSC_VER template using is_signed_int128 = typename std::conditional::value || std::is_same::value, std::true_type, std::false_type>::type; template using is_unsigned_int128 = typename std::conditional::value || std::is_same::value, std::true_type, std::false_type>::type; template using make_unsigned_int128 = typename std::conditional::value, __uint128_t, unsigned __int128>; template using is_integral = typename std::conditional::value || is_signed_int128::value || is_unsigned_int128::value, std::true_type, std::false_type>::type; template using is_signed_int = typename std::conditional<(is_integral::value && std::is_signed::value) || is_signed_int128::value, std::true_type, std::false_type>::type; template using is_unsigned_int = typename std::conditional<(is_integral::value && std::is_unsigned::value) || is_unsigned_int128::value, std::true_type, std::false_type>::type; template using to_unsigned = typename std::conditional< is_signed_int128::value, make_unsigned_int128, typename std::conditional::value, std::make_unsigned, std::common_type>::type>::type; #else template using is_integral = typename std::is_integral; template using is_signed_int = typename std::conditional::value && std::is_signed::value, std::true_type, std::false_type>::type; template using is_unsigned_int = typename std::conditional::value && std::is_unsigned::value, std::true_type, std::false_type>::type; template using to_unsigned = typename std::conditional::value, std::make_unsigned, std::common_type>::type; #endif template using is_signed_int_t = std::enable_if_t::value>; template using is_unsigned_int_t = std::enable_if_t::value>; template using to_unsigned_t = typename to_unsigned::type; } // namespace internal } // namespace atcoder #include #include #include #ifdef _MSC_VER #include #endif namespace atcoder { namespace internal { struct modint_base {}; struct static_modint_base : modint_base {}; template using is_modint = std::is_base_of; template using is_modint_t = std::enable_if_t::value>; } // namespace internal template * = nullptr> struct static_modint : internal::static_modint_base { using mint = static_modint; public: static constexpr int mod() { return m; } static mint raw(int v) { mint x; x._v = v; return x; } static_modint() : _v(0) {} template * = nullptr> static_modint(T v) { long long x = (long long)(v % (long long)(umod())); if (x < 0) x += umod(); _v = (unsigned int)(x); } template * = nullptr> static_modint(T v) { _v = (unsigned int)(v % umod()); } static_modint(bool v) { _v = ((unsigned int)(v) % umod()); } unsigned int val() const { return _v; } mint& operator++() { _v++; if (_v == umod()) _v = 0; return *this; } mint& operator--() { if (_v == 0) _v = umod(); _v--; return *this; } mint operator++(int) { mint result = *this; ++*this; return result; } mint operator--(int) { mint result = *this; --*this; return result; } mint& operator+=(const mint& rhs) { _v += rhs._v; if (_v >= umod()) _v -= umod(); return *this; } mint& operator-=(const mint& rhs) { _v -= rhs._v; if (_v >= umod()) _v += umod(); return *this; } mint& operator*=(const mint& rhs) { unsigned long long z = _v; z *= rhs._v; _v = (unsigned int)(z % umod()); return *this; } mint& operator/=(const mint& rhs) { return *this = *this * rhs.inv(); } mint operator+() const { return *this; } mint operator-() const { return mint() - *this; } mint pow(long long n) const { assert(0 <= n); mint x = *this, r = 1; while (n) { if (n & 1) r *= x; x *= x; n >>= 1; } return r; } mint inv() const { if (prime) { assert(_v); return pow(umod() - 2); } else { auto eg = internal::inv_gcd(_v, m); assert(eg.first == 1); return eg.second; } } friend mint operator+(const mint& lhs, const mint& rhs) { return mint(lhs) += rhs; } friend mint operator-(const mint& lhs, const mint& rhs) { return mint(lhs) -= rhs; } friend mint operator*(const mint& lhs, const mint& rhs) { return mint(lhs) *= rhs; } friend mint operator/(const mint& lhs, const mint& rhs) { return mint(lhs) /= rhs; } friend bool operator==(const mint& lhs, const mint& rhs) { return lhs._v == rhs._v; } friend bool operator!=(const mint& lhs, const mint& rhs) { return lhs._v != rhs._v; } private: unsigned int _v; static constexpr unsigned int umod() { return m; } static constexpr bool prime = internal::is_prime; }; template struct dynamic_modint : internal::modint_base { using mint = dynamic_modint; public: static int mod() { return (int)(bt.umod()); } static void set_mod(int m) { assert(1 <= m); bt = internal::barrett(m); } static mint raw(int v) { mint x; x._v = v; return x; } dynamic_modint() : _v(0) {} template * = nullptr> dynamic_modint(T v) { long long x = (long long)(v % (long long)(mod())); if (x < 0) x += mod(); _v = (unsigned int)(x); } template * = nullptr> dynamic_modint(T v) { _v = (unsigned int)(v % mod()); } dynamic_modint(bool v) { _v = ((unsigned int)(v) % mod()); } unsigned int val() const { return _v; } mint& operator++() { _v++; if (_v == umod()) _v = 0; return *this; } mint& operator--() { if (_v == 0) _v = umod(); _v--; return *this; } mint operator++(int) { mint result = *this; ++*this; return result; } mint operator--(int) { mint result = *this; --*this; return result; } mint& operator+=(const mint& rhs) { _v += rhs._v; if (_v >= umod()) _v -= umod(); return *this; } mint& operator-=(const mint& rhs) { _v += mod() - rhs._v; if (_v >= umod()) _v -= umod(); return *this; } mint& operator*=(const mint& rhs) { _v = bt.mul(_v, rhs._v); return *this; } mint& operator/=(const mint& rhs) { return *this = *this * rhs.inv(); } mint operator+() const { return *this; } mint operator-() const { return mint() - *this; } mint pow(long long n) const { assert(0 <= n); mint x = *this, r = 1; while (n) { if (n & 1) r *= x; x *= x; n >>= 1; } return r; } mint inv() const { auto eg = internal::inv_gcd(_v, mod()); assert(eg.first == 1); return eg.second; } friend mint operator+(const mint& lhs, const mint& rhs) { return mint(lhs) += rhs; } friend mint operator-(const mint& lhs, const mint& rhs) { return mint(lhs) -= rhs; } friend mint operator*(const mint& lhs, const mint& rhs) { return mint(lhs) *= rhs; } friend mint operator/(const mint& lhs, const mint& rhs) { return mint(lhs) /= rhs; } friend bool operator==(const mint& lhs, const mint& rhs) { return lhs._v == rhs._v; } friend bool operator!=(const mint& lhs, const mint& rhs) { return lhs._v != rhs._v; } private: unsigned int _v; static internal::barrett bt; static unsigned int umod() { return bt.umod(); } }; template internal::barrett dynamic_modint::bt = 998244353; using modint998244353 = static_modint<998244353>; using modint1000000007 = static_modint<1000000007>; using modint = dynamic_modint<-1>; namespace internal { template using is_static_modint = std::is_base_of; template using is_static_modint_t = std::enable_if_t::value>; template struct is_dynamic_modint : public std::false_type {}; template struct is_dynamic_modint> : public std::true_type {}; template using is_dynamic_modint_t = std::enable_if_t::value>; } // namespace internal } // namespace atcoder using mint=atcoder::modint1000000007; #line 4 "cpplib/math/ACL_modint_base.hpp" std::ostream& operator<<(std::ostream& lhs, const mint& rhs) noexcept { lhs << rhs.val(); return lhs; } std::istream& operator>>(std::istream& lhs,mint& rhs) noexcept { long long x; lhs >> x; rhs=x; return lhs; } static int MOD_NOW=-1; static int sz=0; static std::vectorfact_table,fact_inv_table; void update(int x){ if(MOD_NOW!=mint::mod()||sz==0){ fact_table.assign(1,1); fact_inv_table.assign(1,1); sz=1; } while(sz<=x){ fact_table.resize(sz*2); fact_inv_table.resize(sz*2); for(int i=sz;i=sz;--i){ fact_inv_table[i]=fact_inv_table[i+1]*(i+1); } sz*=2; } } inline mint fact(int x){ assert(x>=0); update(x); return fact_table[x]; } inline mint fact_inv(int x){ assert(x>=0); update(x); return fact_inv_table[x]; } inline mint comb(int x,int y){ if(x<0||x struct maybe{ bool _is_none; T val; maybe():_is_none(true){} maybe(T val):_is_none(false),val(val){} T unwrap()const{ assert(!_is_none); return val; } T unwrap_or(T e)const{ return _is_none?e:val; } bool is_none()const{return _is_none;} bool is_some()const{return !_is_none;} }; template auto expand(F op){ return [&op](const maybe& s,const maybe& t){ if(s.is_none())return t; if(t.is_none())return s; return maybe(op(s.unwrap(),t.unwrap())); }; } #line 4 "cpplib/segment_tree/segment_tree.hpp" /** * @brief セグメント木 * @see https://en.wikipedia.org/wiki/Segment_tree */ template class segment_tree{ using i64=long long; struct node; using np=node*; struct node{ maybeval=maybe(); np ch[2]={nullptr,nullptr}; node(){} }; np root=new node(); i64 n=1; i64 sz; F op; public: segment_tree(){} segment_tree(i64 sz,F op=F()):sz(sz),op(op){ while(n<=sz)n<<=1; } maybe get(i64 a,i64 b){ return get(a,b,0,n,root); } void apply(i64 x,T val){ apply(x,val,0,n,root); } void apply_left(i64 x,T val){ apply_left(x,val,0,n,root); } void change(i64 x,T val){ change(x,val,0,n,root); } maybe get(i64 a,i64 b,i64 l,i64 r,np t){ if(!t)return maybe(); auto f=expand(op); if(r<=a||b<=l)return maybe(); if(a<=l&&r<=b)return t->val; i64 m=(l+r)/2; return f(get(a,b,l,m,t->ch[0]),get(a,b,m,r,t->ch[1])); } void apply(i64 x,T val,i64 l,i64 r,np t){ auto f=expand(op); if(!t->ch[0])t->ch[0]=new node(); if(!t->ch[1])t->ch[1]=new node(); if(l<=x&&xval=f(t->val,val); i64 m=(l+r)/2; if(r-l>1){ apply(x,val,l,m,t->ch[0]); apply(x,val,m,r,t->ch[1]); } } } void apply_left(i64 x,T val,i64 l,i64 r,np t){ if(!t->ch[0])t->ch[0]=new node(); if(!t->ch[1])t->ch[1]=new node(); auto f=expand(op); if(l<=x&&xval=f(val,t->val); i64 m=(l+r)/2; if(r-l>1){ apply_left(x,val,l,m,t->ch[0]); apply_left(x,val,m,r,t->ch[1]); } } } maybe change(i64 x,T val,i64 l,i64 r,np t){ if(!t->ch[0])t->ch[0]=new node(); if(!t->ch[1])t->ch[1]=new node(); auto f=expand(op); if(l<=x&&x1){ i64 m=(l+r)/2; return t->val=f(change(x,val,l,m,t->ch[0]),change(x,val,m,r,t->ch[1])); }else{ return t->val=f(t->val,val); } } } }; #line 4 "code.cpp" int main(){ lint n; cin>>n; vec a(n); rep(i,n)cin>>a[i]; vec b(n+1); rep(i,n)b[i+1]=b[i]^a[i]; mapm; vectordp(n+1); dp[0]=1; mint tmp=1; rep(i,1,n+1){ dp[i]+=tmp; tmp+=dp[i]; if(m.count(b[i])){ tmp-=dp[m[b[i]]]; } m[b[i]]=i; } cout<