cp/codeforces/506/1029a.cc

76 lines
1.5 KiB
C++

#include <bits/stdc++.h> // {{{
#include <version>
#ifdef __cpp_lib_ranges_enumerate
#include <ranges>
namespace rv = std::views;
namespace rs = std::ranges;
#endif
#pragma GCC optimize("O2,unroll-loops")
#pragma GCC target("avx2,bmi,bmi2,lzcnt,popcnt")
using namespace std;
using i16 = int16_t;
using u16 = uint16_t;
using i32 = int32_t;
using u32 = uint32_t;
using i64 = int64_t;
using u64 = uint64_t;
using f64 = double;
using f128 = long double;
#if __cplusplus >= 202002L
template <typename T>
constexpr T MIN = std::numeric_limits<T>::min();
template <typename T>
constexpr T MAX = std::numeric_limits<T>::max();
#endif
#ifdef LOCAL
#define db(...) std::print(__VA_ARGS__)
#define dbln(...) std::println(__VA_ARGS__)
#else
#define db(...)
#define dbln(...)
#endif
// }}}
void solve() {
u32 n, k;
cin >> n >> k;
string t;
cin >> t;
vector<int> pi(n, 0);
for (int i = 1, j = 0; i < n; ++i) {
while (j && t[i] != t[j]) j = pi[j-1];
if (t[i] == t[j]) ++j;
pi[i] = j;
}
int ov = pi[n-1];
print("{}", t);
for (u32 _ = 1; _ < k; ++_) {
for (u32 h = ov; h < n; ++h) print("{}", t[h]);
}
println();
}
int main() { // {{{
std::cin.exceptions(std::cin.failbit);
#ifdef LOCAL
std::cerr.rdbuf(std::cout.rdbuf());
std::cout.setf(std::ios::unitbuf);
std::cerr.setf(std::ios::unitbuf);
#else
std::cin.tie(nullptr)->sync_with_stdio(false);
#endif
u32 tc = 1;
// std::cin >> tc;
for (u32 t = 0; t < tc; ++t) {
solve();
}
return 0;
}
// }}}