#line 1 "test.cpp" //#pragma GCC target("avx2") //#pragma GCC optimize("O3") //#pragma GCC optimize("unroll-loops") #include using namespace std; #ifdef LOCAL #include #define debug(...) debug_print::multi_print(#__VA_ARGS__, __VA_ARGS__) #else #define debug(...) (static_cast(0)) #endif using ll = long long; using ld = long double; using pll = pair; using pii = pair; using vi = vector; using vvi = vector; using vvvi = vector; using vl = vector; using vvl = vector; using vvvl = vector; using vpii = vector; using vpll = vector; using vs = vector; template using pq = priority_queue,greater>; #define overload4(_1, _2, _3, _4, name, ...) name #define overload3(a,b,c,name,...) name #define rep1(n) for (ll UNUSED_NUMBER = 0; UNUSED_NUMBER < (n); ++UNUSED_NUMBER) #define rep2(i, n) for (ll i = 0; i < (n); ++i) #define rep3(i, a, b) for (ll i = (a); i < (b); ++i) #define rep4(i, a, b, c) for (ll i = (a); i < (b); i += (c)) #define rep(...) overload4(__VA_ARGS__, rep4, rep3, rep2, rep1)(__VA_ARGS__) #define rrep1(n) for(ll i = (n) - 1;i >= 0;i--) #define rrep2(i,n) for(ll i = (n) - 1;i >= 0;i--) #define rrep3(i,a,b) for(ll i = (b) - 1;i >= (a);i--) #define rrep4(i,a,b,c) for(ll i = (a) + ((b)-(a)-1) / (c) * (c);i >= (a);i -= c) #define rrep(...) overload4(__VA_ARGS__, rrep4, rrep3, rrep2, rrep1)(__VA_ARGS__) #define all1(i) begin(i),end(i) #define all2(i,a) begin(i),begin(i)+a #define all3(i,a,b) begin(i)+a,begin(i)+b #define all(...) overload3(__VA_ARGS__, all3, all2, all1)(__VA_ARGS__) #define sum(...) accumulate(all(__VA_ARGS__),0LL) template bool chmin(T &a, const T &b){ if(a > b){ a = b; return 1; } else return 0; } template bool chmax(T &a, const T &b){ if(a < b){ a = b; return 1; } else return 0; } template auto min(const T& a){ return *min_element(all(a)); } template auto max(const T& a){ return *max_element(all(a)); } template void in(Ts&... t); #define INT(...) int __VA_ARGS__; in(__VA_ARGS__) #define LL(...) ll __VA_ARGS__; in(__VA_ARGS__) #define STR(...) string __VA_ARGS__; in(__VA_ARGS__) #define CHR(...) char __VA_ARGS__; in(__VA_ARGS__) #define DBL(...) double __VA_ARGS__; in(__VA_ARGS__) #define LD(...) ld __VA_ARGS__; in(__VA_ARGS__) #define VEC(type, name, size) vector name(size); in(name) #define VV(type, name, h, w) vector> name(h, vector(w)); in(name) ll intpow(ll a, ll b){ ll ans = 1; while(b){if(b & 1) ans *= a; a *= a; b /= 2;} return ans;} ll modpow(ll a, ll b, ll p){ ll ans = 1; a %= p;while(b){ if(b & 1) (ans *= a) %= p; (a *= a) %= p; b /= 2; } return ans; } ll GCD(ll a,ll b) { if(a == 0 || b == 0) return a + b; if(a % b == 0) return b; else return GCD(b,a%b);} ll LCM(ll a,ll b) { if(a == 0) return b; if(b == 0) return a;return a / GCD(a,b) * b;} namespace IO{ #define VOID(a) decltype(void(a)) struct setting{ setting(){cin.tie(nullptr); ios::sync_with_stdio(false);fixed(cout); cout.precision(12);}} setting; template struct P : P{}; template<> struct P<0>{}; template void i(T& t){ i(t, P<3>{}); } void i(vector::reference t, P<3>){ int a; i(a); t = a; } template auto i(T& t, P<2>) -> VOID(cin >> t){ cin >> t; } template auto i(T& t, P<1>) -> VOID(begin(t)){ for(auto&& x : t) i(x); } template void ituple(T& t, index_sequence){ in(get(t)...);} template auto i(T& t, P<0>) -> VOID(tuple_size{}){ ituple(t, make_index_sequence::value>{});} #undef VOID } #define unpack(a) (void)initializer_list{(a, 0)...} template void in(Ts&... t){ unpack(IO :: i(t)); } #undef unpack static const double PI = 3.1415926535897932; template struct REC { F f; REC(F &&f_) : f(forward(f_)) {} template auto operator()(Args &&...args) const { return f(*this, forward(args)...); }}; //constexpr int mod = 1000000007; constexpr int mod = 998244353; #line 2 "library/inner/inner-hash.hpp" namespace inner { using i64 = long long; using u64 = unsigned long long; using u128 = __uint128_t; template struct Hash: array { using array::operator[]; static constexpr int n = BASE_NUM; Hash():array() {} static constexpr u64 md = (1ull << 61) - 1; constexpr static Hash set(const i64 &a) { Hash res; fill(begin(res),end(res),cast(a)); return res; } Hash &operator +=(const Hash &r) { for(int i = 0;i < n; i++) { if(((*this)[i] += r[i]) >= md) (*this[i]) -= md; } return *this; } Hash &operator+=(const i64 &r) { u64 s = cast(r); for (int i = 0; i < n; i++) { if (((*this)[i] += s) >= md) (*this)[i] -= md; } return *this; } Hash &operator-=(const Hash &r) { for (int i = 0; i < n; i++) { if (((*this)[i] += md - r[i]) >= md) (*this)[i] -= md; } return *this; } Hash &operator-=(const i64 &r) { u64 s = cast(r); for (int i = 0; i < n; i++) { if (((*this)[i] += md - s) >= md) (*this)[i] -= md; } return *this; } Hash &operator*=(const Hash &r) { for (int i = 0; i < n; i++) { (*this)[i] = modmul((*this)[i], r[i]); } return *this; } Hash &operator*=(const i64 &r) { u64 s = cast(r); for (int i = 0; i < n; i++) { (*this)[i] = modmul((*this)[i], s); } return *this; } Hash operator+(const Hash &r) { return Hash(*this) += r; } Hash operator+(const i64 &r) { return Hash(*this) += r; } Hash operator-(const Hash &r) { return Hash(*this) -= r; } Hash operator-(const i64 &r) { return Hash(*this) -= r; } Hash operator*(const Hash &r) { return Hash(*this) *= r; } Hash operator*(const i64 &r) { return Hash(*this) *= r; } Hash operator-() const { Hash res; for (int i = 0; i < n; i++) { res[i] = (*this)[i] == 0 ? 0 : md - (*this)[i]; } return res; } friend Hash pfma(const Hash &a, const Hash &b, const Hash &c) { Hash res; for (int i = 0; i < n; i++) { res[i] = modfma(a[i], b[i], c[i]); } return res; } friend Hash pfma(const Hash &a, const Hash &b, const i64 &c) { Hash res; u64 s = cast(c); for (int i = 0; i < n; i++) { res[i] = modfma(a[i], b[i], s); } return res; } static Hash get_basis() { static auto rand_time = chrono::duration_cast( chrono::high_resolution_clock::now().time_since_epoch()) .count(); static mt19937_64 rng(rand_time); Hash h; for (int i = 0; i < n; i++) { while (isPrimitive(h[i] = rng() % (md - 1) + 1) == false); } return h; } private: static u64 modpow(u64 a, u64 b) { u64 r = 1; for (a %= md; b; a = modmul(a, a), b >>= 1) r = modmul(r, a); return r; } static bool isPrimitive(u64 x) { for (auto &d : vector{2, 3, 5, 7, 11, 13, 31, 41, 61, 151, 331, 1321}) if (modpow(x, (md - 1) / d) <= 1) return false; return true; } static inline constexpr u64 cast(const long long &a) { return a < 0 ? a + md : a; } static inline constexpr u64 modmul(const u64 &a, const u64 &b) { u128 ret = u128(a) * b; ret = (ret & md) + (ret >> 61); return ret >= md ? ret - md : ret; } static inline constexpr u64 modfma(const u64 &a, const u64 &b, const u64 &c) { u128 ret = u128(a) * b + c; ret = (ret & md) + (ret >> 61); return ret >= md ? ret - md : ret; } }; } #line 3 "library/string/Rolling-Hash.hpp" template struct RollingHash { using Hash = inner::Hash; Str data; vector hs,pw; int s; static Hash basis; RollingHash(const Str &S = Str()) {build(S);} void build(const Str &S) { data = S; s = S.size(); hs.resize(s + 1); pw.resize(s + 1); pw[0] = Hash::set(1); hs[0] = Hash::set(0); for(int i = 1;i <= s; i++) { pw[i] = pw[i-1] * basis; hs[i] = pfma(hs[i-1],basis,S[i-1]); } } Hash get(int l,int r = -1) const{ if(r == -1)r = s; return pfma(hs[l],-pw[r-l],hs[r]); } static Hash get_hash(const Str &T) { Hash ret = Hash::set(0); for(int i = 0;i < (int)T.size();i++) { ret = pfma(ret,basis,T[i]); } return ret; } int find(Str &T, int lower = 0) const { auto ths = get_Hash(T); for(int i = lower; i <= s -(int)T.size();i++) { if(ths == get(i,i + (int)T.size())) return i; } return -1; } friend int LCP(const RollingHash &a,RollingHash &b,int astart,int bstart) { int ok = 0,ng = min(a.size() - astart,b.size() - bstart) + 1; while (ok + 1 < ng) { int med = (ok + ng) / 2; (a.get(astart,med + astart) == b.get(bstart,med + bstart) ? ok:ng) = med; } return ok; } friend int strcmp(const RollingHash &a,RollingHash &b,int astart,int bstart,int aend = -1,int bend = -1) { if (aend == -1) aend = a.size(); if (bend == -1) bend = b.size(); if (aend - astart == bend - bstart) { if(a.get(astart,aend) == b.get(bstart,bend)) { return 0; } } else if(aend - astart < bend - bstart) { if(a.get(astart,aend) == b.get(bstart,bstart + aend - astart)) { return 1; } } else { if(a.get(astart,astart + bend - bstart) == b.get(bstart,bend)) { return -1; } } if (a.data[astart] < b.data[bstart]) {return 1;} else if (a.data[astart] > b.data[bstart]) {return -1;} int n = min({LCP(a,b,astart,bstart),aend - astart,bend - bstart}); return astart + n == aend ? bstart + n == bend ? 0 : 1 : bstart + n == bend ? -1 : a.data[astart + n] < b.data[bstart + n] ? 1 : -1; } int size() const{return s;} }; template typename RollingHash::Hash RollingHash::basis = inner::Hash::get_basis(); #line 87 "test.cpp" using roriha = RollingHash; int main() { STR(s); int n = s.size(); string t = s; reverse(all(t)); roriha rs(s),rt(t); vi dp(n+1); rep(i,1,n+1) dp[0] = n; rep(i,1,n+1) { rep(j,i) { if(rs.get(j,i) == rt.get(n-i,n-j)) chmax(dp[i],min(dp[j],int(i-j))); } } cout << dp[n] << '\n'; }