//#ifndef LOCAL
//#pragma GCC optimize ("Ofast")
//#pragma GCC optimize ("unroll-loops")
//#endif
#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace std;
using namespace __gnu_pbds;
template<typename T> using ordered_set = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
template<typename T> using indexed_multiset = tree<T, null_type, less_equal<T>, rb_tree_tag, tree_order_statistics_node_update>;
#define int int64_t
#define vi vector
#define ss second
#define ff first
#define TESTCASES
#define all(x) (x).begin(), (x).end()
const int mod = 1E9+7;
const int MAXN=200000;
const int inf=1e18;
#ifndef khos
#define debug(...) 42
#endif 
#define debug(args...)                                                         \
    {                                                                          \
        cout << "[" << #args << "]: ";                                         \
        my::debug::debug_out(args);                                            \
        cout << endl;                                                          \
    }
namespace my::debug {
using std::cout;
template <typename T, typename = void>
struct is_container : std::false_type {};
template <typename T>
struct is_container<T, std::void_t<decltype(std::begin(std::declval<T>()))>>
    : std::true_type {};
template <typename T>
constexpr bool is_container_v = is_container<T>::value;
template <typename Test, template <typename...> class Ref>
struct is_specialization : std::false_type {};
template <template <typename...> class Ref, typename... Args>
struct is_specialization<Ref<Args...>, Ref> : std::true_type {};
template <typename Test, template <typename...> class Ref>
constexpr bool is_specialization_v = is_specialization<Test, Ref>::value;
// https://stackoverflow.com/a/47563100
template <std::size_t N>
struct num {
    static const constexpr auto value = N;
};
template <class F, std::size_t... Is>
void for_(F func, std::index_sequence<Is...>) {
    (func(num<Is>{}), ...);
}
template <std::size_t N, typename F>
void for_(F func) {
    for_(func, std::make_index_sequence<N>());
}
template <typename T>
constexpr auto is_coutable(int)
    -> decltype(std::cout << std::declval<T>(), std::true_type{}) {
    return std::true_type{};
}
template <typename T>
constexpr std::false_type is_coutable(...) {
    return std::false_type{};
}
template <typename T>
constexpr bool is_coutable_v = decltype(is_coutable<T>(0))::value;
template <typename T>
void single_out(T x) {
    if constexpr (std::is_same_v<T, std::string> | std::is_same_v<T, char*> ||
                  std::is_same_v<T, const char*>) {
        cout << '"' << x << '"';
    } else if constexpr (std::is_same_v<T, char>) {
        cout << x;
    } else if constexpr (std::is_integral_v<T> || std::is_floating_point_v<T> ||
                         std::is_enum_v<T> || std::is_pointer_v<T>) {
        cout << x;
    } else if constexpr (is_specialization_v<T, std::pair>) {
        cout << "(";
        single_out(x.first);
        cout << ", ";
        single_out(x.second);
        cout << ")";
    } else if constexpr (is_specialization_v<T, std::tuple>) {
        cout << "(";
        std::string sep = "";
        for_<std::tuple_size_v<T>>([&](auto i) {
            cout << exchange(sep, ", ");
            single_out(std::get<i.value>(x));
        });
        cout << ")";
    } else if constexpr (is_specialization_v<T, std::map> ||
                         is_specialization_v<T, std::unordered_map>) {
        cout << "{";
        std::string sep = "";
        for (auto [k, v] : x) {
            cout << exchange(sep, ", ");
            single_out(k);
            cout << ": ";
            single_out(v);
        }
        cout << "}";
    } else if constexpr (is_container_v<T>) {
        if constexpr (is_specialization_v<T, std::vector>) {
            cout << "[";
        } else cout << "{";
        std::string sep = "";
        for (auto i : x) {
            cout << exchange(sep, ", ");
            single_out(i);
        }
        if constexpr (is_specialization_v<T, std::vector>) {
            cout << "]";
        } else cout << "}";
    }
    // types without iterator, f*** you, c++ comittee
    else if constexpr (is_specialization_v<T, std::queue>) {
        cout << "{";
        std::string sep = "";
        while (x.size()) {
            cout << exchange(sep, ", ");
            single_out(x.front());
            x.pop();
        }
        cout << "}";
    } else if constexpr (is_specialization_v<T, std::stack> ||
                         is_specialization_v<T, std::priority_queue>) {
        std::vector<
            std::remove_cv_t<std::remove_reference_t<decltype(x.top())>>>
            v;
        while (x.size()) {
            v.push_back(x.top());
            x.pop();
        }
        if constexpr (is_specialization_v<T, std::stack>)
            std::reverse(v.begin(), v.end());
        cout << "{";
        std::string sep = "";
        for (auto i : v) {
            cout << exchange(sep, ", ");
            single_out(i);
        }
        cout << "}";
    }
    // lastly, if the expression (cout << x) compiles, use it
    else {
        static_assert(is_coutable_v<T>, "The type given to debug() is not supported.");
        cout << x;
    }
}
template <typename T, typename... Rest>
void debug_out(T, Rest...);
void debug_out();
template <typename T, typename... Rest>
void debug_out(T x, Rest... rest) {
    // single_out<std::remove_cv_t<std::decay_t<T>>>(x);
    single_out<std::remove_cv_t<T>>(x);
    if (sizeof...(rest) > 0) cout << ", ";
    debug_out(rest...);
}
void debug_out() {
}
}; // namespace my::debug
void solution(){
    int n,k;
    cin >> n >> k;
    string s;
    cin >> s;
    stack<pair<char,int>> st;
    for(int i=0; i<n; i++){
        if(st.size()==0 || st.top().ff!=s[i]){
            st.push({s[i],1});
        }
        else {
            st.push({s[i],st.top().ss+1});
        }
        if(st.top().ss==k){
            char c=st.top().ff;
            while(st.size()>0 && c==st.top().ff)st.pop();
        }
    }
    string ans;
    while(st.size()){
        ans+=st.top().ff;
        st.pop();
    }
    reverse(all(ans));
    cout << ans;
}
int32_t main(){
    clock_t tStart = clock();
    #ifdef khos
        freopen("input.txt", "r", stdin);
        freopen("output.txt", "w", stdout);
    #endif
    std::ios::sync_with_stdio(0); cin.tie(0); cout.tie(0);
    int q = 1;
    #ifdef TESTCASES
        // cin >> q;
    #endif
    while(q--) {
        solution();
        cout << '\n';
    }
    cerr<<fixed<<setprecision(3)<<"\nTime Taken: "<<(double)(clock()- tStart)/CLOCKS_PER_SEC<<endl;
}
컴파일 시 표준 에러 (stderr) 메시지
treasure.cpp:27: warning: "debug" redefined
   27 | #define debug(args...)                                                         \
      | 
treasure.cpp:24: note: this is the location of the previous definition
   24 | #define debug(...) 42
      || # | Verdict | Execution time | Memory | Grader output | 
|---|
| Fetching results... | 
| # | Verdict | Execution time | Memory | Grader output | 
|---|
| Fetching results... |