結果
問題 | No.2858 Make a Palindrome |
ユーザー |
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提出日時 | 2024-08-25 14:36:20 |
言語 | C++17 (gcc 13.3.0 + boost 1.87.0) |
結果 |
AC
|
実行時間 | 136 ms / 3,000 ms |
コード長 | 13,980 bytes |
コンパイル時間 | 2,332 ms |
コンパイル使用メモリ | 210,820 KB |
最終ジャッジ日時 | 2025-02-24 01:12:15 |
ジャッジサーバーID (参考情報) |
judge3 / judge3 |
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ファイルパターン | 結果 |
---|---|
other | AC * 40 |
ソースコード
#line 1 "main.cpp"#include<bits/stdc++.h>using namespace std;// #pragma GCC target("avx,avx2")// #pragma GCC optimize("O3")// #pragma GCC optimize("unroll-loops")#ifdef LOCAL#include <debug.hpp>#define debug(...) debug_print::multi_print(#__VA_ARGS__, __VA_ARGS__)#else#define debug(...) (static_cast<void>(0))#endifusing namespace std;using ll = long long;using ull = unsigned long long;using ld = long double;using pll = pair<ll,ll>;using pii = pair<int,int>;using vi = vector<int>;using vvi = vector<vi>;using vvvi = vector<vvi>;using vl = vector<ll>;using vvl = vector<vl>;using vvvl = vector<vvl>;using vul = vector<ull>;using vpii = vector<pii>;using vvpii = vector<vpii>;using vpll = vector<pll>;using vs = vector<string>;template<class T> using pq = priority_queue<T,vector<T>, greater<T>>;#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<class T> bool chmin(T &a, const T &b){ if(a > b){ a = b; return 1; } else return 0; }template<class T> bool chmax(T &a, const T &b){ if(a < b){ a = b; return 1; } else return 0; }template<class T> auto min(const T& a){return *min_element(all(a));}template<class T> auto max(const T& a){return *max_element(all(a));}template<class... Ts> 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<type> name(size); in(name)#define VV(type, name, h, w) vector<vector<type>> name(h, vector<type>(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;if(a < 0) a += p;while(b){ if(b & 1) (ans *= a) %= p; (a *= a) %= p; b /= 2; } return ans; }bool is_clamp(ll val,ll low,ll high) {return low <= val && val < high;}void Yes() {cout << "Yes\n";return;}void No() {cout << "No\n";return;}void YES() {cout << "YES\n";return;}void NO() {cout << "NO\n";return;}template <typename T>T floor(T a, T b) {return a / b - (a % b && (a ^ b) < 0);}template <typename T>T ceil(T x, T y) {return floor(x + y - 1, y);}template <typename T>T bmod(T x, T y) {return x - y * floor(x, y);}template <typename T>pair<T, T> divmod(T x, T y) {T q = floor(x, y);return {q, x - q * y};}namespace IO{#define VOID(a) decltype(void(a))struct setting{ setting(){cin.tie(nullptr); ios::sync_with_stdio(false);fixed(cout); cout.precision(15);}} setting;template<int I> struct P : P<I-1>{};template<> struct P<0>{};template<class T> void i(T& t){ i(t, P<3>{}); }void i(vector<bool>::reference t, P<3>){ int a; i(a); t = a; }template<class T> auto i(T& t, P<2>) -> VOID(cin >> t){ cin >> t; }template<class T> auto i(T& t, P<1>) -> VOID(begin(t)){ for(auto&& x : t) i(x); }template<class T, size_t... idx> void ituple(T& t, index_sequence<idx...>){in(get<idx>(t)...);}template<class T> auto i(T& t, P<0>) -> VOID(tuple_size<T>{}){ituple(t, make_index_sequence<tuple_size<T>::value>{});}#undef VOID}#define unpack(a) (void)initializer_list<int>{(a, 0)...}template<class... Ts> void in(Ts&... t){ unpack(IO :: i(t)); }#undef unpackconstexpr long double PI = 3.141592653589793238462643383279L;template <class F> struct REC {F f;REC(F &&f_) : f(forward<F>(f_)) {}template <class... Args> auto operator()(Args &&...args) const { return f(*this, forward<Args>(args)...); }};constexpr int mod = 998244353;//constexpr int mod = 1000000007;#line 2 "library/string/manacher.hpp"template<typename T>vector<int> manacher(T s,bool calc_even = true) {if(calc_even) {int n = (int)s.size();assert(n > 0);s.resize(2 * n - 1);for(int i = n - 1; i >= 0; i--) {s[2 * i] = s[i];}auto d = *min_element(begin(s), end(s));for(int i = 0; i < n - 1; i++) {s[2 * i + 1] = d;}}int n = (int)s.size();vector<int> rad(n);int i = 0, j = 0;while(i < n) {while(i - j >= 0 && i + j < n && s[i - j] == s[i + j]) ++j;rad[i] = j;int k = 1;while(i - k >= 0 && i + k < n && k + rad[i - k] < j) {rad[i + k] = rad[i - k];++k;}i += k, j -= k;}if(calc_even) {for(int i = 0; i < n; i++) {if(((i ^ rad[i]) & 1) == 0) rad[i]--;}} else {for(auto &&x: rad) x = 2 * x - 1;}return rad;}#line 2 "library/inner/inner-hash.hpp"namespace inner {using i64 = long long;using u64 = unsigned long long;using u128 = __int128_t;template <int BASE_NUM = 2>struct Hash: array<u64, BASE_NUM> {using array<u64, BASE_NUM>::operator[];static constexpr int n = BASE_NUM;Hash():array<u64, BASE_NUM>() {}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;}// a * b + c (mod p)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;}Hash pow(long long e) {Hash a{*this}, res{Hash::set(1)};for (; e; a *= a, e >>= 1) {if (e & 1) res *= a;}return res;}static Hash get_basis() {static auto rand_time =chrono::duration_cast<chrono::nanoseconds>(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<u64>{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 <typename Str, int BASE_NUM = 2>struct RollingHash {using Hash = inner::Hash<BASE_NUM>;Str data;vector<Hash> 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;}// a + b の hash を返す// 引数 : a, b, b の長さstatic Hash unite(Hash a, Hash b, long long bsize) {return pfma(a, basis.pow(bsize), b);}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<int>({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 Str,int BASE_NUM>typename RollingHash<Str,BASE_NUM>::Hash RollingHash<Str,BASE_NUM>::basis = inner::Hash<BASE_NUM>::get_basis();#line 101 "main.cpp"using roriha = RollingHash<string,2>;void solve() {INT(n,m);STR(s);auto ret1 = manacher(s);if(max(ret1) >= m) {cout << 1 << '\n';return;}string t = s + s;auto ret2 = manacher(t);if(max(ret2) >= m) {cout << 2 << '\n';return;}roriha rs(s);reverse(all(s));roriha rt(s);int ans = 2e9;rep(i,n) {if(rs.get(0,i) == rt.get(n-i,n) && rs.get(i,n) == rt.get(0,n-i)) {int M = max(i,n-i);int x = m / n;int rem = m % n;if(i == 0) {if(rem) x++;}else {if(M >= rem) x++;else x += 2;}chmin(ans,x);}}if(ans == (int)2e9) cout << -1 << '\n';else cout << ans << '\n';}int main() {INT(TT);while(TT--) solve();}