/** * code generated by JHelper * More info: https://github.com/AlexeyDmitriev/JHelper * @author */ //@formatter:off #pragma GCC optimize("Ofast") #include using namespace std; #include #include #include #include #include namespace atcoder { namespace internal { std::vector sa_naive(const std::vector& s) { int n = int(s.size()); std::vector sa(n); std::iota(sa.begin(), sa.end(), 0); std::sort(sa.begin(), sa.end(), [&](int l, int r) { if (l == r) return false; while (l < n && r < n) { if (s[l] != s[r]) return s[l] < s[r]; l++; r++; } return l == n; }); return sa; } std::vector sa_doubling(const std::vector& s) { int n = int(s.size()); std::vector sa(n), rnk = s, tmp(n); std::iota(sa.begin(), sa.end(), 0); for (int k = 1; k < n; k *= 2) { auto cmp = [&](int x, int y) { if (rnk[x] != rnk[y]) return rnk[x] < rnk[y]; int rx = x + k < n ? rnk[x + k] : -1; int ry = y + k < n ? rnk[y + k] : -1; return rx < ry; }; std::sort(sa.begin(), sa.end(), cmp); tmp[sa[0]] = 0; for (int i = 1; i < n; i++) { tmp[sa[i]] = tmp[sa[i - 1]] + (cmp(sa[i - 1], sa[i]) ? 1 : 0); } std::swap(tmp, rnk); } return sa; } template std::vector sa_is(const std::vector& s, int upper) { int n = int(s.size()); if (n == 0) return {}; if (n == 1) return {0}; if (n == 2) { if (s[0] < s[1]) { return {0, 1}; } else { return {1, 0}; } } if (n < THRESHOLD_NAIVE) { return sa_naive(s); } if (n < THRESHOLD_DOUBLING) { return sa_doubling(s); } std::vector sa(n); std::vector ls(n); for (int i = n - 2; i >= 0; i--) { ls[i] = (s[i] == s[i + 1]) ? ls[i + 1] : (s[i] < s[i + 1]); } std::vector sum_l(upper + 1), sum_s(upper + 1); for (int i = 0; i < n; i++) { if (!ls[i]) { sum_s[s[i]]++; } else { sum_l[s[i] + 1]++; } } for (int i = 0; i <= upper; i++) { sum_s[i] += sum_l[i]; if (i < upper) sum_l[i + 1] += sum_s[i]; } auto induce = [&](const std::vector& lms) { std::fill(sa.begin(), sa.end(), -1); std::vector buf(upper + 1); std::copy(sum_s.begin(), sum_s.end(), buf.begin()); for (auto d : lms) { if (d == n) continue; sa[buf[s[d]]++] = d; } std::copy(sum_l.begin(), sum_l.end(), buf.begin()); sa[buf[s[n - 1]]++] = n - 1; for (int i = 0; i < n; i++) { int v = sa[i]; if (v >= 1 && !ls[v - 1]) { sa[buf[s[v - 1]]++] = v - 1; } } std::copy(sum_l.begin(), sum_l.end(), buf.begin()); for (int i = n - 1; i >= 0; i--) { int v = sa[i]; if (v >= 1 && ls[v - 1]) { sa[--buf[s[v - 1] + 1]] = v - 1; } } }; std::vector lms_map(n + 1, -1); int m = 0; for (int i = 1; i < n; i++) { if (!ls[i - 1] && ls[i]) { lms_map[i] = m++; } } std::vector lms; lms.reserve(m); for (int i = 1; i < n; i++) { if (!ls[i - 1] && ls[i]) { lms.push_back(i); } } induce(lms); if (m) { std::vector sorted_lms; sorted_lms.reserve(m); for (int v : sa) { if (lms_map[v] != -1) sorted_lms.push_back(v); } std::vector rec_s(m); int rec_upper = 0; rec_s[lms_map[sorted_lms[0]]] = 0; for (int i = 1; i < m; i++) { int l = sorted_lms[i - 1], r = sorted_lms[i]; int end_l = (lms_map[l] + 1 < m) ? lms[lms_map[l] + 1] : n; int end_r = (lms_map[r] + 1 < m) ? lms[lms_map[r] + 1] : n; bool same = true; if (end_l - l != end_r - r) { same = false; } else { while (l < end_l) { if (s[l] != s[r]) { break; } l++; r++; } if (l == n || s[l] != s[r]) same = false; } if (!same) rec_upper++; rec_s[lms_map[sorted_lms[i]]] = rec_upper; } auto rec_sa = sa_is(rec_s, rec_upper); for (int i = 0; i < m; i++) { sorted_lms[i] = lms[rec_sa[i]]; } induce(sorted_lms); } return sa; } } // namespace internal std::vector suffix_array(const std::vector& s, int upper) { assert(0 <= upper); for (int d : s) { assert(0 <= d && d <= upper); } auto sa = internal::sa_is(s, upper); return sa; } template std::vector suffix_array(const std::vector& s) { int n = int(s.size()); std::vector idx(n); iota(idx.begin(), idx.end(), 0); sort(idx.begin(), idx.end(), [&](int l, int r) { return s[l] < s[r]; }); std::vector s2(n); int now = 0; for (int i = 0; i < n; i++) { if (i && s[idx[i - 1]] != s[idx[i]]) now++; s2[idx[i]] = now; } return internal::sa_is(s2, now); } std::vector suffix_array(const std::string& s) { int n = int(s.size()); std::vector s2(n); for (int i = 0; i < n; i++) { s2[i] = s[i]; } return internal::sa_is(s2, 255); } template std::vector lcp_array(const std::vector& s, const std::vector& sa) { int n = int(s.size()); assert(n >= 1); std::vector rnk(n); for (int i = 0; i < n; i++) { rnk[sa[i]] = i; } std::vector lcp(n - 1); int h = 0; for (int i = 0; i < n; i++) { if (h > 0) h--; if (rnk[i] == 0) continue; int j = sa[rnk[i] - 1]; for (; j + h < n && i + h < n; h++) { if (s[j + h] != s[i + h]) break; } lcp[rnk[i] - 1] = h; } return lcp; } std::vector lcp_array(const std::string& s, const std::vector& sa) { int n = int(s.size()); std::vector s2(n); for (int i = 0; i < n; i++) { s2[i] = s[i]; } return lcp_array(s2, sa); } template std::vector z_algorithm(const std::vector& s) { int n = int(s.size()); if (n == 0) return {}; std::vector z(n); z[0] = 0; for (int i = 1, j = 0; i < n; i++) { int& k = z[i]; k = (j + z[j] <= i) ? 0 : std::min(j + z[j] - i, z[i - j]); while (i + k < n && s[k] == s[i + k]) k++; if (j + z[j] < i + z[i]) j = i; } z[0] = n; return z; } std::vector z_algorithm(const std::string& s) { int n = int(s.size()); std::vector s2(n); for (int i = 0; i < n; i++) { s2[i] = s[i]; } return z_algorithm(s2); } } // namespace atcoder //@formatter:off #define rep(i, n) for (int i = 0; i < (n); ++i) #define drep(i, n) for (int i = (n)-1; i >= 0; --i) #define srep(i, s, t) for (int i = s; i < t; ++i) #define rng(a) a.begin(), a.end() #define rrng(a) a.rbegin(), a.rend() using ll = long long; using P = pair; using VI = vector; using VVI = vector; using VVVI = vector; using VVVVI = vector; using VL = vector; using VVL = vector; using VVVL = vector; using VVVVL = vector; using VP = vector

; using VVP = vector>; using VS = vector; using VC = vector; using VVC = vector>; using VD = vector; using VVD = vector>; using VVVD = vector; using I_I = pair; const int INF = (int)1e9 + 10; // int max > 2*10^9 const long long INFL = (ll)2e18 + 10; // ll max > 9*10^18 const int JU_5 = 100000; const int JU_6 = 1000000; const ll JU_9 = 1000000000; const ll JU_18 = JU_9*JU_9; #define YES cout << "YES" << endl #define NO cout << "NO" << endl #define Yes cout << "Yes" << endl #define No cout << "No" << endl template pair operator+(const pair &a, const pair &b) { return make_pair(a.first + b.first, a.second + b.second); } template pair operator-(const pair &a, const pair &b) { return make_pair(a.first - b.first, a.second - b.second); } template pair operator*(const pair &a, const pair &b) { return make_pair(a.first * b.first, a.second * b.second); } template pair operator/(const pair &a, const pair &b) { return make_pair(a.first / b.first, a.second / b.second); } // #define MOD 1000000007 #define MOD 998244353 #define pmod(x,y) ((x%y)+y)%y /********** libs **********/ //@formatter:off // jhelper 用変数 ostream *__cout; istream *__cin; void _init_io(std::istream &cin, std::ostream &cout) { // 入出力高速化用 ios::sync_with_stdio(false); cin.tie(nullptr); cout << std::setprecision(30); // jhelper 用 __cout = &cout; __cin = &cin; } //@formatter:off /* デバッグ用 出力 */ template ostream &operator<<(ostream &os, const deque &vec) { os << "deq["; for (auto v: vec) os << v << ","; os << "]"; return os; } template ostream &operator<<(ostream &os, const set &vec) { os << "{"; for (auto v: vec) os << v << ","; os << "}"; return os; } template ostream &operator<<(ostream &os, const unordered_set &vec) { os << "{"; for (auto v: vec) os << v << ","; os << "}"; return os; } template ostream &operator<<(ostream &os, const multiset &vec) { os << "{"; for (auto v: vec) os << v << ","; os << "}"; return os; } template ostream &operator<<(ostream &os, const unordered_multiset &vec) { os << "{"; for (auto v: vec) os << v << ","; os << "}"; return os; } template ostream &operator<<(ostream &os, const pair &pa) { os << "(" << pa.first << "," << pa.second << ")"; return os; } template ostream &operator<<(ostream &os, const map &mp) { os << "{"; for (auto v: mp) os << v.first << "=>" << v.second << ","; os << "}"; return os; } template ostream &operator<<(ostream &os, const unordered_map &mp) { os << "{"; for (auto v: mp) os << v.first << "=>" << v.second << ","; os << "}"; return os; } // print like python // src: https://qiita.com/Lily0727K/items/06cb1d6da8a436369eed ///////////////////////////////////////////////////////// void print() { *__cout << '\n'; } template void print(Head &&head, Tail &&... tail) { *__cout << head; if (sizeof...(tail) != 0) *__cout << " "; print(forward(tail)...); } template void print(vector &vec) { for (auto &a: vec) { *__cout << a; if (&a != &vec.back()) *__cout << " "; } *__cout << '\n'; } template void print(vector> &df) { for (auto &vec: df) { print(vec); } } // endl なし void Print() {} template void Print(Head &&head, Tail &&... tail) { *__cout << head; if (sizeof...(tail) != 0) *__cout << " "; Print(forward(tail)...); } template void Print(vector &vec) { for (auto &a: vec) { *__cout << a; if (&a != &vec.back()) *__cout << " "; } } //@formatter:off /* * org: https://atcoder.jp/contests/abc213/submissions/24901856 * jhelper で使用するため, 全部 cin での入力にしている. (現状のレベルでは困らないので) */ template void scan(T& a){ *__cin >> a; } template void scan(vector&); template void scan(pair&); template void scan(vector& a){ for(auto&& i : a) scan(i); } template void scan(pair& p){ scan(p.first); scan(p.second); } template void scan(T (&a)[size]){ for(auto&& i : a) scan(i); } void in(){} template void in(T&... a){ (void)initializer_list{ (scan(a), 0)... }; } #define let_v(type,name,...) vectorname(__VA_ARGS__) #define let_V(type,name,size) vectorname(size);in(name) #define let_vv(type,name,h,...) vector>name(h,vector(__VA_ARGS__)) #define let_VV(type,name,h,w) vector>name(h,vector(w));in(name) #define let_vvv(type,name,h,w,...) vector>>name(h,vector>(w,vector(__VA_ARGS__))) #define let_vvvv(type,name,h,w,x,...) vector>>>name(h,vector>>(w,vector>(x,vector(__VA_ARGS__)))) #define let_vvvvv(type,name,h,w,x,y,...) vector>>>>name(h,vector>>>(w,vector>>(x,vector>(y,vector(__VA_ARGS__))))) /* string 入力を vector で受け取るみたいな */ vector let_CharVec() { string s; *__cin >> s; return {s.begin(), s.end()}; } //@formatter:off //ll gcd(ll a, ll b) { return b ? gcd(b, a % b) : a; } ll lcm(ll a, ll b) { return a / gcd(a, b) * b; } template bool chmax(T& a, C b) { if (a < b) { a = b; return true; } return false; } template bool chmin(T& a, C b) { if (a > b) { a = b; return true; } return false; } template T sum(const vector& v) { T res = 0; for (size_t i = 0; i < v.size(); ++i) res += v[i]; return res; } //template //T min(T a, C b) { return a <= b ? a : T(b); } // //template //T max(T a, C b) { return a >= b ? a : T(b); } template vector> idx_pair(vector &vals) { vector> ans; rep(i, vals.size()) { ans.emplace_back(vals[i], i); } return ans; } template int argmax(vector &vals){ if(vals.size()==0)return -1; int res=0; for(int i = 1;ivals[res])res=i; } return res; } template int argmin(vector &vals){ if(vals.size()==0)return -1; int res=0; for(int i = 1;i> t; while (t--) _solve(cin, cout); } //@formatter:on void _solve(std::istream &cin, std::ostream &cout) { // code int n; string s; cin >> n >> s; auto res = atcoder::suffix_array(s); auto z = atcoder::z_algorithm(s); // print(res); // print(z); ll tot = 0; bool flg = false; rep(i, n) { int idx = res[i]; if (idx == 0)flg = true; else if (flg) tot++; } drep(i, n) { if (i <= n / 2)break; if (z[i] == n - i)tot++; } print(tot); } }; int main() { unko solver; std::istream& in(std::cin); std::ostream& out(std::cout); solver.solve(in, out); return 0; }