結果
| 問題 | No.1020 Reverse |
| ユーザー |
 バイト
|
| 提出日時 | 2020-04-18 23:33:20 |
| 言語 | C++17 (gcc 12.3.0 + boost 1.83.0) |
| 結果 |
AC
|
| 実行時間 | 3 ms / 2,000 ms |
| コード長 | 20,968 bytes |
| コンパイル時間 | 2,936 ms |
| コンパイル使用メモリ | 230,668 KB |
| 実行使用メモリ | 6,824 KB |
| 最終ジャッジ日時 | 2024-10-04 00:31:56 |
| 合計ジャッジ時間 | 3,883 ms |
|
ジャッジサーバーID （参考情報） |
judge4 / judge2 |
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テストケース
テストケース表示| 入力 | 結果 | 実行時間 実行使用メモリ |
|---|---|---|
| testcase_00 | AC | 1 ms
6,816 KB |
| testcase_01 | AC | 2 ms
6,820 KB |
| testcase_02 | AC | 2 ms
6,820 KB |
| testcase_03 | AC | 2 ms
6,816 KB |
| testcase_04 | AC | 2 ms
6,820 KB |
| testcase_05 | AC | 2 ms
6,816 KB |
| testcase_06 | AC | 2 ms
6,816 KB |
| testcase_07 | AC | 2 ms
6,820 KB |
| testcase_08 | AC | 3 ms
6,820 KB |
| testcase_09 | AC | 2 ms
6,816 KB |
| testcase_10 | AC | 3 ms
6,824 KB |
| testcase_11 | AC | 3 ms
6,816 KB |
| testcase_12 | AC | 3 ms
6,816 KB |
| testcase_13 | AC | 3 ms
6,820 KB |
| testcase_14 | AC | 3 ms
6,816 KB |
| testcase_15 | AC | 3 ms
6,820 KB |
| testcase_16 | AC | 3 ms
6,816 KB |
| testcase_17 | AC | 3 ms
6,816 KB |
ソースコード
//tempaa
//#pragma GCC optimize ("-O3")
#ifdef _DEBUG
#include<cassert>
#include "bits_stdc++.h"
#else
#include <bits/stdc++.h>
#endif
#define r_ return
#define v_ vector
#define t_T template<class T>
using namespace std;
//@起動時
struct initon {
initon() {
cin.tie(0);
ios::sync_with_stdio(false);
cout.setf(ios::fixed);
cout.precision(3);
srand((unsigned) clock() + (unsigned) time(NULL));
};
} __initon;
//衝突対策
#define ws ___ws
#define over4(o1, o2, o3, o4, name, ...) name
#define int long long
#define ll long long
#define double long double
#define ull unsigned long long
using dou = double;
using itn = int;
using str = string;
using bo= bool;
#define au auto
using P = pair<ll, ll>;
#define fi first
#define se second
#define vec v_
#define beg begin
#define rbeg rbegin
#define con continue
#define bre break
#define brk break
#define is ==
using vi = v_<ll>;
using vb = v_<bool>;
using vs = v_<string>;
using vd = v_<double>;
using vc = v_<char>;
using vp = v_<P>;
//#define V v_
#define vvt0(t) v_<v_<t>>
#define vvt1(t, a) v_<v_<t>>a
#define vvt2(t, a, b) v_<v_<t>>a(b)
#define vvt3(t, a, b, c) v_<v_<t>> a(b,v_<t>(c))
#define vvt4(t, a, b, c, d) v_<v_<t>> a(b,v_<t>(c,d))
#define vvi(...) over4(__VA_ARGS__,vvt4,vvt3,vvt2 ,vvt1,vvt0)(ll,__VA_ARGS__)
#define vvb(...) over4(__VA_ARGS__,vvt4,vvt3,vvt2 ,vvt1,vvt0)(bool,__VA_ARGS__)
#define vvs(...) over4(__VA_ARGS__,vvt4,vvt3,vvt2 ,vvt1,vvt0)(string,__VA_ARGS__)
#define vvd(...) over4(__VA_ARGS__,vvt4,vvt3,vvt2 ,vvt1,vvt0)(double,__VA_ARGS__)
#define vvc(...) over4(__VA_ARGS__,vvt4,vvt3,vvt2 ,vvt1,vvt0)(char,__VA_ARGS__)
#define vvp(...) over4(__VA_ARGS__,vvt4,vvt3,vvt2 ,vvt1,vvt0)(P,__VA_ARGS__)
#define v3i(a, b, c, d) v_<v_<vi>> a(b, v_<vi>(c, vi(d)))
#define v3d(a, b, c, d) v_<v_<vd>> a(b, v_<vd>(c, vd(d)))
#define v3m(a, b, c, d) v_<v_<vm>> a(b, v_<vm>(c, vm(d)))
#define PQ priority_queue<ll, v_<ll>, greater<ll> >
#define tos to_string
using mapi = map<int, int>;
using mapd = map<dou, int>;
using mapc = map<char, int>;
using maps = map<str, int>;
using seti = set<int>;
using setd = set<dou>;
using setc = set<char>;
using sets = set<str>;
using qui = queue<int>;
#define bset bitset
#define uset unordered_set
#define mset multiset
#define umap unordered_map
#define umapi unordered_map<int,int>
#define umapp unordered_map<P,int>
#define mmap multimap
//マクロ 繰り返し
#define _overloadrep(_1, _2, _3, _4, name, ...) name
# define _rep(i, n) for(int i = 0,_lim=n; i < _lim ; i++)
#define repi(i, m, n) for(int i = m,_lim=n; i < _lim ; i++)
#define repadd(i, m, n, ad) for(int i = m,_lim=n; i < _lim ; i+= ad)
#define rep(...) _overloadrep(__VA_ARGS__,repadd,repi,_rep,)(__VA_ARGS__)
#define _rer(i, n) for(int i = n; i >= 0 ; i--)
#define reri(i, m, n) for(int i = m,_lim=n; i >= _lim ; i--)
#define rerdec(i, m, n, dec) for(int i = m,_lim=n; i >= _lim ; i-=dec)
#define rer(...) _overloadrep(__VA_ARGS__,rerdec,reri,_rer,)(__VA_ARGS__)
#define fora(a, b) for(auto&& a : b)
//マクロ 定数
#define k3 1010
#define k4 10101
#define k5 101010
#define k6 1010101
#define k7 10101010
t_T T MAX() { r_ numeric_limits<T>::max(); }
t_T T MIN() { r_ numeric_limits<T>::min(); }
const int inf = (int) 1e9 + 100;
const ll linf = (ll) 1e18 + 100;
t_T T INF() { r_ MAX<T>() / 2; }
template<> signed INF() { r_ inf; }
template<> ll INF() { r_ linf; }
template<> double INF() { r_ (double) linf * linf; }
const double eps = 1e-9;
const double PI = 3.1415926535897932384626433832795029L;
ll ma = numeric_limits<ll>::min();
ll mi = numeric_limits<ll>::max();
const int y4[] = {-1, 1, 0, 0};
const int x4[] = {0, 0, -1, 1};
const int y8[] = {0, 1, 0, -1, -1, 1, 1, -1};
const int x8[] = {1, 0, -1, 0, 1, -1, 1, -1};
//マクロ省略形 関数等
#define sz(a) ((int)(a).size())
#define rs resize
#define mp make_pair
#define mt make_tuple
#define pb push_back
#define pf push_front
#define eb emplace_back
#define all(a) (a).begin(),(a).end()
#define rall(a) (a).rbegin(),(a).rend()
/*@formatter:off*/
inline void sort(string &a) { sort(all(a)); }
t_T inline void sort(v_<T> &a) { sort(all(a)); };
t_T inline void rsort(v_<T> &a) { sort(all(a), greater<T>()); };
template<class U> inline void sortp(v_<U> &a, v_<U> &b) { vp c; int n = sz(a); assert(n == sz(b)); rep(i, n)c.eb(a[i], b[i]); sort(c); rep(i, n) { a[i] = c[i].first; b[i] = c[i].second;; }};//F = T<T>
//例えばr_ p.fi + p.se;
template<class U> inline void rsortp(v_<U> &a, v_<U> &b) { vp c; int n = sz(a); assert(n == sz(b)); rep(i, n)c.eb(a[i], b[i]); rsort(c); rep(i, n) { a[i] = c[i].first; b[i] = c[i].second; }};
template<typename V, typename T>
void fill(V &xx, const T vall) {xx = vall;}
template<typename V, typename T>
void fill(v_<V> &vecc, const T vall) {for (auto &&vx: vecc) fill(vx, vall);}
//@汎用便利関数 入力
template<typename T = int> T _in() {T x;cin >> x;r_ (x);}
#define _overloadin(_1, _2, _3, _4, name, ...) name
#define in0() _in()
#define in1(a) cin>>a
#define in2(a, b) cin>>a>>b
#define in3(a, b, c) cin>>a>>b>>c
#define in4(a, b, c, d) cin>>a>>b>>c>>d
#define in(...) _overloadin(__VA_ARGS__,in4,in3,in2 ,in1,in0)(__VA_ARGS__)
#define _overloaddin(_1, _2, _3, _4, name, ...) name
#define din1(a) int a;cin>>a
#define din2(a, b) int a,b;cin>>a>>b
#define din3(a, b, c) int a,b,c;cin>>a>>b>>c
#define din4(a, b, c, d) int a,b,c,d;cin>>a>>b>>c>>d
#define din(...) _overloadin(__VA_ARGS__,din4,din3,din2 ,din1)(__VA_ARGS__)
#define _overloaddind(_1, _2, _3, _4, name, ...) name
#define din1d(a) int a;cin>>a;a--
#define din2d(a, b) int a,b;cin>>a>>b;a--,b--
#define din3d(a, b, c) int a,b,c;cin>>a>>b>>c;a--,b--,c--
#define din4d(a, b, c, d) int a,b,c,d;cin>>a>>b>>c>>d;;a--,b--,c--,d--
#define dind(...) _overloaddind(__VA_ARGS__,din4d,din3d,din2d ,din1d)(__VA_ARGS__)
template<typename W, typename H> void resize(W &vec_, const H head) { vec_.resize(head); }
template<typename W, typename H, typename ... T> void resize(W &vec_, const H &head, const T ... tail) {vec_.resize(head);for (auto &v: vec_)resize(v, tail...);}
string sin() { r_ _in<string>(); }
ll lin() { r_ _in<ll>(); }
t_T void na(v_<T> &a, ll n) {a.resize(n);rep(i, n)cin >> a[i];}
#define dna(a, n) vi a; na(a, n);/*nを複数使うと n==in()の時バグる事に注意*/
#define dnad(a, n) vi a; nad(a, n);
t_T void nad(v_<T> &a, ll n) {a.resize(n);rep(i, n)cin >> a[i], a[i]--;}
template<class T, class U> void na2(v_<T> &a, v_<U> &b, ll n) {a.resize(n);b.resize(n);rep(i, n)cin >> a[i] >> b[i];}
#define dna2(a, b, n) vi a,b; na2(a,b,n);
template<class T, class U, class W> void na3(v_<T> &a, v_<U> &b, v_<W> &c, ll n) {a.resize(n);b.resize(n);c.resize(n);rep(i, n)cin >> a[i] >> b[i] >> c[i];}
#define nt(a, h, w) resize(a,h,w);rep(nthi,h)rep(ntwi,w) cin >> a[nthi][ntwi];
#define ntd(a, h, w) resize(a,h,w);rep(ntdhi,h)rep(ntdwi,w) cin >> a[ntdhi][ntdwi], a[ntdhi][ntdwi]--;
#define ntp(a, h, w) resize(a,h+2,w+2);fill(a,'#');rep(ntphi,1,h+1)rep(ntpwi,1,w+1) cin >> a[ntphi][ntpwi];
#define dnt(S, h, w) vvi(S,h,w);nt(S,h,w);
#define dntc(S, h, w) vvc(S,h,w);nt(S,h,w);
#define dnts(S, h, w) vvs(S,h,w);nt(S,h,w);
//デバッグ
#define sp << " " <<
constexpr int DEB_LEN =20;
constexpr int DEB_LEN_H =12;
string deb_tos(const int &v) { if (abs(v) == inf || abs(v) == linf)return "e"; else return to_string(v); }
template<class T> string deb_tos(const T &a) {stringstream ss;ss << a;return ss.str();}
template<class T> string deb_tos(const vector<T> &a, ll W = inf) { stringstream ss; if (W == inf)W = min(sz(a), DEB_LEN); if (sz(a) == 0)return ss.str(); rep(i, W) { ss << deb_tos(a[i]); if (typeid(a[i]) == typeid(P)) { ss << endl; } else { ss << " "; } } return ss.str();}
template<class T> string deb_tos(const vector<vector<T> > &a, vi H, vi W, int key = -1) { stringstream ss; ss << endl; vi lens(sz(W)); fora(h, H) { rep(wi, sz(W)) { lens[wi] = max(lens[wi], sz(deb_tos(a[h][W[wi]])) + 1); lens[wi] = max(lens[wi], sz(deb_tos(W[wi])) + 1); } } if (key == -1)ss << " *|"; else ss << " " << key << "|"; int wi = 0; fora(w, W) { ss << std::right << std::setw(lens[wi]) << w; wi++; } ss << "" << endl; rep(i, sz(W))rep(_, lens[i]) ss << "_"; rep(i, 3)ss << "_"; ss << "" << endl; fora(h, H) { ss << std::right << std::setw(2) << h << "|"; int wi = 0; fora(w, W) { ss << std::right << std::setw(lens[wi]) << deb_tos(a[h][w]); wi++; } ss << "" << endl; } return ss.str();}
template<class T> string deb_tos(const vector<vector<T> > &a, ll H = inf, ll W = inf, int key = -1) { H = (H != inf) ? H : min({H, sz(a), DEB_LEN_H}); W = min({W, sz(a[0]), DEB_LEN_H}); vi hs, ws; rep(h, H) { hs.push_back(h); } rep(w, W) { ws.push_back(w); } return deb_tos(a, hs, ws, key);}
template<class T> string deb_tos(const vector<vector<vector<T> > > &a, ll H = inf) { stringstream ss; if (H == inf)H = DEB_LEN_H; H = min(H, sz(a)); rep(i, H) { ss << endl; ss << deb_tos(a[i], inf, inf, i); } return ss.str();}
template<class T, size_t A> string deb_tos(T (&a)[A]) { return deb_tos(vector<T>(begin(a), end(a))); }
template<class T, size_t A, size_t B> string deb_tos(T (&a)[A][B]) { return deb_tos(vector<vector<T> >(begin(a), end(a))); }
template<class T, size_t A, size_t B, size_t C> string deb_tos(T (&a)[A][B][C]) { return deb_tos(vector<vector<vector<T> > >(begin(a), end(a))); }
#define debugName(VariableName) # VariableName
#define _deb1(x) cerr << debugName(x)<<" = "<<deb_tos(x) << endl
#define _deb2(x, y) cerr << debugName(x)<<" = "<<deb_tos(x)<<", "<< debugName(y)<<" = "<<deb_tos(y)<< endl
#define _deb3(x, y, z) cerr << debugName(x)<<" = "<<deb_tos(x) << ", " << debugName(y)<<" = "<<deb_tos(y) <<", " debugName(z)<<" = "<<deb_tos(z) <<endl
#define _deb4(x, y, z, a) cerr << debugName(x)<<" = "<<deb_tos(x) <<", " << debugName(y)<<" = "<<deb_tos(y) <<", " << debugName(z)<<" = "<<deb_tos(z) <<", " << debugName(a)<<" = "<<deb_tos(a)<<endl
#define _deb5(x, y, z, a, b) cerr << debugName(x)<<" = "<<deb_tos(x) <<", " << debugName(y)<<" = "<<deb_tos(y) <<", " << debugName(z)<<" = "<<deb_tos(z) <<", " << debugName(a)<<" = "<<deb_tos(a)<<", " << debugName(b)<<" = "<<deb_tos(b)<<endl
#define _overloadebug(_1, _2, _3, _4, _5, name, ...) name
#define debug(...) _overloadebug(__VA_ARGS__,_deb5,_deb4,_deb3,_deb2,_deb1)(__VA_ARGS__)
#ifdef _DEBUG
#define deb(...) _overloadebug(__VA_ARGS__,_deb5,_deb4,_deb3,_deb2,_deb1)(__VA_ARGS__)
#else
#define deb(...) ;
#endif
#define debugline(x) cerr << x << " " << "(L:" << __LINE__ << ")" << '\n'
ll gcd(ll a, ll b) { r_ b ? gcd(b, a % b) : a; }
ll gcd(vi b) {ll res = b[0];for (auto &&v :b)res = gcd(v, res);r_ res;}
ll lcm(ll a, ll b) { r_ a / gcd(a, b) * b; }
ll rev(ll a) { ll res = 0; while (a) { res *= 10; res += a % 10; a /= 10; } r_ res;}
t_T v_<T> rev(const v_<T> &a) { auto b = a; reverse(all(b)); r_ b;}
str rev(const str &a) {str s = a;reverse(all(s));r_ s;}
ll ceil(ll a, ll b) {if (b == 0) {cerr<<"ceil"<<endl;exit(1);r_ -1;} else r_ (a + b - 1) / b;}
ll sqrt(ll a) { if (a < 0) { cerr<<"sqrt"<<endl; exit(1); } ll res = (ll) std::sqrt(a); while (res * res < a)res++; r_ res;}
double log(double e, double x) { r_ log(x) / log(e); }
ll sig(ll t) { r_ (1 + t) * t / 2; }
ll sig(ll s, ll t) { r_ (s + t) * (t - s + 1) / 2; }
vi divisors(int v) { vi res; double lim = std::sqrt(v); rep(i, 1, lim+1){ if (v % i == 0) { res.pb(i); if (i != v / i)res.pb(v / i); } } r_ res;}
vb isPrime;
vi primes;
void setPrime() { int len = 4010101; isPrime.resize(4010101); fill(isPrime, true); isPrime[0] = isPrime[1] = false; for (int i = 2; i <= sqrt(len) + 5; ++i) { if (!isPrime[i])continue; for (int j = 2; i * j < len; ++j) { isPrime[i * j] = false; } } rep(i, len)if (isPrime[i])primes.pb(i);}
vi factorization(int v) { int tv = v; vi res; if (isPrime.size() == 0)setPrime(); for (auto &&p :primes) { if (v % p == 0)res.push_back(p); while (v % p == 0) { v /= p; } if (v == 1 || p * p > tv)break; } if (v > 1)res.pb(v); r_ res;}
inline bool inside(int h, int w, int H, int W) { r_ h >= 0 && w >= 0 && h < H && w < W; }
inline bool inside(int v, int l, int r) { r_ l <= v && v < r; }
t_T v_<T> ruiv(v_<T> &a) { v_<T> ret(a.size() + 1); rep(i, a.size())ret[i + 1] = ret[i] + a[i]; r_ ret;}
//imoは0-indexed
//ruiは1-indexed
t_T v_<T> imo(v_<T> &v) { v_<T> ret = v; rep(i, sz(ret) - 1)ret[i + 1] += ret[i]; r_ ret;}
#define ins inside
ll u0(ll a) { r_ a < 0 ? 0 : a; }
t_T v_<T> u(const v_<T> &a) {
v_<T> ret = a;fora(v, ret)v = u0(v);r_ ret;}
#define MIN(a) numeric_limits<a>::min()
#define MAX(a) numeric_limits<a>::max()
template<class T, class U> pair<T,U> operator+(const pair<T,U> &a, const pair<T,U> & b) {return pair<T,U>(a.fi+b.fi,a.se+b.se);}
void yn(bool a) {
if (a)cout << "yes" << endl;
else cout << "no" << endl;
}
void Yn(bool a) {
if (a)cout << "Yes" << endl;
else cout << "No" << endl;
}
void YN(bool a) {
if (a)cout << "YES" << endl;
else cout << "NO" << endl;
}
void fyn(bool a) {
if (a)cout << "yes" << endl;
else cout << "no" << endl;
exit(0);
}
void fYn(bool a) {
if (a)cout << "Yes" << endl;
else cout << "No" << endl;
exit(0);
}
void fYN(bool a) {
if (a)cout << "YES" << endl;
else cout << "NO" << endl;
exit(0);
}
void Possible(bool a) {
if (a)cout << "Possible" << endl;
else cout << "Impossible" << endl;
exit(0);
}
void POSSIBLE(bool a) {
if (a)cout << "POSSIBLE" << endl;
else cout << "IMPOSSIBLE" << endl;
exit(0);
}
template<class T, class U> set<T> &operator+=(set<T> &a, U v) {
a.insert(v);
r_ a;
}
template<class T, class U> v_<T> &operator+=(v_<T> &a, U v) {
a.push_back(v);
r_ a;
}
template<class T> v_<T>& operator+=(v_<T> & a,const v_<T> & b){
fora(v, b)a += v;
return a;
}
t_T T sum(v_<T> &v, int s = 0, int t = inf) { T ret = 0; rep(i, s, min(sz(v), t))ret += v[i]; r_ ret;}
void mod(int &a, int m) { a = (a % m + m) % m; }
template<class F> inline int mgr(int ok, int ng, F f) {
#define _mgrbody int mid = (ok + ng) / 2; if (f(mid))ok = mid; else ng = mid;
if (ok < ng)while (ng - ok > 1) { _mgrbody } else while (ok - ng > 1) { _mgrbody }
r_ ok;
}
template<class F> inline int mgr(int ok, int ng, int second, F f) {
#define _mgrbody2 int mid = (ok + ng) / 2; if (f(mid, second))ok = mid; else ng = mid;
if (ok < ng) while (ng - ok > 1) { _mgrbody2 } else while (ok - ng > 1) { _mgrbody2 }
r_ ok;
}
template<typename T> ostream &operator<<(ostream &os, v_<T> &m) { rep(i, sz(m)){os << m[i];if(i < sz(m)-1)os<<" ";} r_ os;}
ostream &operator<<(ostream &os, v_<char> &m) {rep(i, sz(m)){os << m[i];} r_ os;}
template<typename T> ostream &operator<<(ostream &os, v_<v_<T>> &m) {rep(i, sz(m)){os << m[i]; if(i < sz(m)-1)os << endl;} r_ os;}
constexpr bool bget(ll m, int keta) { r_ (m >> keta) & 1; }
int bget(ll m, int keta, int sinsuu) {m /= (ll) pow(sinsuu, keta);r_ m % sinsuu;}
ll bit(int n) { r_ (1LL << (n)); }
ll bit(int n, int sinsuu) { r_ (ll) pow(sinsuu, n); }
int mask(int n) { r_ (1ll << n) - 1; }
#define bcou __builtin_popcountll
template<class T, class U> inline bool chma(T &a, const U &b) {if (a < b) {a = b;r_ true;}r_ false;}
template<class U> inline bool chma(const U &b) { r_ chma(ma, b); }
template<class T, class U> inline bool chmi(T &a, const U &b) { if (b < a) { a = b; r_ true; } r_ false;}
template<class U> inline bool chmi(const U &b) { r_ chmi(mi, b); }
#define unique(v) v.erase( unique(v.begin(), v.end()), v.end() );
int max(vi &a) { int res = a[0]; fora(v, a) { res = max(res, v); } r_ res;}
int min(vi &a) { int res = a[0]; fora(v, a) { res = min(res, v); } r_ res;}
template<typename T> class fixed_point : T {public: explicit constexpr fixed_point(T &&t) noexcept: T(std::forward<T>(t)) {} template<typename... Args> constexpr decltype(auto) operator()(Args &&... args) const { r_ T::operator()(*this, std::forward<Args>(args)...); }};template<typename T> static inline constexpr decltype(auto) fix(T &&t) noexcept { r_ fixed_point<T>{std::forward<T>(t)}; }
constexpr ll h4[] = {1, -1, 0, 0};
constexpr ll w4[] = {0, 0, -1, 1};
constexpr ll h8[] = {0, 1, 0, -1, -1, 1, 1, -1};
constexpr ll w8[] = {1, 0, -1, 0, 1, -1, 1, -1};
int mei_inc(int h, int w, int H, int W, int i) {while (++i < 4) { if (inside(h + h4[i], w + w4[i], H, W))r_ i; }r_ i;}
#define mei(nh, nw, h, w) for (int i = mei_inc(h, w, H, W, -1), nh = i<4? h + h4[i] : 0, nw = i<4? w + w4[i] : 0; i < 4; i=mei_inc(h,w,H,W,i), nh = h+h4[i], nw = w+w4[i])
int mei_inc8(int h, int w, int H, int W, int i) { while (++i < 8) { if (inside(h + h8[i], w + w8[i], H, W))r_ i; } r_ i;}
#define mei8(nh, nw, h, w) for (int i = mei_inc8(h, w, H, W, -1), nh = i<8? h + h8[i] : 0, nw = i<8? w + w8[i] : 0; i < 8; i=mei_inc8(h,w,H,W,i), nh = h+h8[i], nw = w+w8[i])
int mei_incv(int h, int w, int H, int W, int i, vp &p) { while (++i < sz(p)) { if (inside(h + p[i].fi, w + p[i].se, H, W))r_ i; } r_ i;}
#define meiv(nh, nw, h, w, p) for (int i = mei_incv(h, w, H, W, -1, p), nh = i<sz(p)? h + p[i].fi : 0, nw = i<sz(p)? w + p[i].se : 0; i < sz(p); i=mei_incv(h,w,H,W,i,p), nh = h+p[i].fi, nw = w+p[i].se)
vi compress(vi &A) { vi B = A; sort(B); unique(B); vi inds(sz(B)); rep(i, sz(A)) { int ind = lower_bound(all(B), A[i]) - B.begin(); inds[ind] = A[i]; A[i] = ind; } return inds;}
vi compress(vi &A, umapi& map){ vi i_v = compress(A); rep(i, sz(i_v)){ map[i_v[i]] = i; } return i_v;}
t_T void out2(T head) { cout << head;}
template<class T, class... U> void out2(T head, U ... tail) { cout << head << " "; out2(tail...);}
template<class T, class... U> void out(T head, U ... tail) { cout << head << " "; out2(tail...); cout << "" << endl;}
t_T void out(T head) { cout << head << endl; }
void out() { cout << "" << endl; }
#define lowerIndex(a, v) (lower_bound(all(a),v)-a.begin())
#define upperIndex(a, v) (upper_bound(all(a),v)-a.begin())
template<typename T> vector<T> make_v(size_t a) { return vector<T>(a); }
template<typename T, typename... Ts> auto make_v(size_t a, Ts... ts) { return vector<decltype(make_v<T>(ts...))>(a, make_v<T>(ts...)); }
#define vni(name, ...) auto name = make_v<ll>(__VA_ARGS__)
#define vnb(name, ...) auto name = make_v<bool>(__VA_ARGS__)
#define vns(name, ...) auto name = make_v<string>(__VA_ARGS__)
#define vnd(name, ...) auto name = make_v<double>(__VA_ARGS__)
#define vnc(name, ...) auto name = make_v<char>(__VA_ARGS__)
#define vnp(name, ...) auto name = make_v<P>(__VA_ARGS__)
#define vn(type, name, ...) auto name = make_v<type>(__VA_ARGS__)
#define VEC vector
/*@formatter:on*/
int N, M, H, W;
vi A, B, C;
#define strs slice_str
struct slice_str {
string S;
slice_str() {}
slice_str(const string &S) : S(S) {}
slice_str(int len, char c) : S(len, c) {}
auto size() { return S.size(); }
char &operator[](int p) { return S[p]; }
string operator[](initializer_list<int> p) {
if (sz(p) == 1) { return S.substr(0, *(p.begin())); }
else if (sz(p) == 2) {
int l = *(p.begin());
int r = *(next(p.begin()));
return S.substr(l, r - l);
}
else {
auto it = p.begin();
int s = *(it++);
int t = *(it++);
int d = *(it);
if (d == -1) {
int s_ = sz(S) - s - 1;
int t_ = sz(S) - t - 1;
return rev(S).substr(s_, t_ - s_);
}
else if (d < 0) {
t = max(-1ll, t);
string ret;
while (s > t) {
ret += S[s];
s += d;
}
return ret;
}
else {
t = min(sz(S), t);
string ret;
while (s < t) {
ret += S[s];
s += d;
}
return ret;
}
}
}
operator string &() { return S; }
template<class T> void operator+=(const T &a) { S += a; }
bool operator==(const slice_str &rhs) { return S == rhs.S; }
};
void solve() {
in(N);
din(K);
str S;
in(S);
str res = S.substr(K - 1);
res += ((N - K + 1) % 2 == 0 ? S.substr(0, K - 1) : rev(S.substr(0, K-1)));
out(res);
}
signed main() {
solve();
r_ 0;
}