Language: C++

#include <bits/stdc++.h>
using namespace std;
#define REP(i, n) for (int i = 0, i##_len = (n); i < i##_len; ++i)
#define FOR(i, s, n) for (int i = (s), i##_len = (n); i < i##_len; ++i)

// https://ei1333.github.io/algorithm/cumulative-sum2d.html
template <class T> struct CumulativeSum2D {
    vector<vector<T>> data;

    CumulativeSum2D(int W, int H) : data(W + 1, vector<int>(H + 1, 0)) {}

    void add(int x, int y, T z) {
        ++x, ++y;
        if (x >= data.size() || y >= data[0].size())
            return;
        data[x][y] += z;
    }

    void build() {
        FOR(i, 1, data.size()) FOR(j, 1, data.size()) {
            data[i][j] += data[i][j - 1] + data[i - 1][j] - data[i - 1][j - 1];
        }
    }

    T query(int sx, int sy, int gx, int gy) {
        return (data[gx][gy] - data[sx][gy] - data[gx][sy] + data[sx][sy]);
    }

    void print() {
        for (auto &x : data) {
            for (auto &y : x) {
                cout << y << " ";
            }
            cout << endl;
        }
    }
};

int main(void) {
    ios::sync_with_stdio(false);
    cin.tie(0);
    char c;
    int n, k, x, y;
    cin >> n >> k;
    CumulativeSum2D<int16_t> s(k * 2, k * 2);
    REP(i, n) {
        cin >> x >> y >> c;
        if (c == 'W') {
            y += k;
        }
        y %= 2 * k;
        if (y >= k) {
            y -= k;
            x += k;
        }
        x %= 2 * k;
        s.add(x, y, 1);
        s.add((x + k) % (2 * k), y + k, 1);
    }
    // 二次元累積和
    s.build();
    // s.print();
    int maxv = 0;
    REP(x, k) REP(y, k) {
        int t = s.query(x, y, x + k, y + k);
        maxv = max({maxv, t, n - t});
    }
    cout << maxv << endl;
    return 0;
}


Compiler output:
a.cc: In instantiation of 'CumulativeSum2D<T>::CumulativeSum2D(int, int) [with T = short int]':
a.cc:45:44:   required from here
   45 |     CumulativeSum2D<int16_t> s(k * 2, k * 2);
      |                                            ^
a.cc:10:37: error: no matching function for call to 'std::vector<std::vector<short int, std::allocator<short int> >, std::allocator<std::vector<short int, std::allocator<short int> > > >::vector(int, std::vector<int>)'
   10 |     CumulativeSum2D(int W, int H) : data(W + 1, vector<int>(H + 1, 0)) {}
      |                                     ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
In file included from /usr/include/c++/14/vector:66,
                 from /usr/include/c++/14/functional:64,
                 from /usr/include/x86_64-linux-gnu/c++/14/bits/stdc++.h:53,
                 from a.cc:1:
/usr/include/c++/14/bits/stl_vector.h:707:9: note: candidate: 'template<class _InputIterator, class> std::vector<_Tp, _Alloc>::vector(_InputIterator, _InputIterator, const allocator_type&) [with <template-parameter-2-2> = _InputIterator; _Tp = std::vector<short int, std::allocator<short int> >; _Alloc = std::allocator<std::vector<short int, std::allocator<short int> > >]'
  707 |         vector(_InputIterator __first, _InputIterator __last,
      |         ^~~~~~
/usr/include/c++/14/bits/stl_vector.h:707:9: note:   template argument deduction/substitution failed:
a.cc:10:37: note:   deduced conflicting types for parameter '_InputIterator' ('int' and 'std::vector<int>')
   10 |     CumulativeSum2D(int W, int H) : data(W + 1, vector<int>(H + 1, 0)) {}
      |                                     ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/14/bits/stl_vector.h:678:7: note: candidate: 'std::vector<_Tp, _Alloc>::vector(std::initializer_list<_Tp>, const allocator_type&) [with _Tp = std::vector<short int, std::allocator<short int> >; _Alloc = std::allocator<std::vector<short int, std::allocator<short int> > >; allocator_type = std::allocator<std::vector<short int, std::allocator<short int> > >]'
  678 |       vector(initializer_list<value_type> __l,
      |       ^~~~~~
/usr/include/c++/14/bits/stl_vector.h:678:43: note:   no known conversion for argument 1 from 'int' to 'std::initializer_list<std::vector<short int, std::allocator<short int> > >'
  678 |       vector(initializer_list<value_type> __l,
      |              ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~
/usr/include/c++/14/bits/stl_vector.h:659:7: note: candidate: 'std::vector<_Tp, _Alloc>::vector(std::vector<_Tp, _Alloc>&&, std::__type_identity_t<_Alloc>&) [with _Tp = std::vector<short int, std::allocator<short int> >; _Alloc = std::allocator<std::vector<short int, std::allocator<short int> > >; std::__type_identity_t<_Alloc> = std::allocator<std::vector<short int, std::allocator<short int> > >]'
  659 |       vector(vector&& __rv, const __type_identity_t<allocator_type>& __m)
      |       ^~~~~~
/usr/include/c++/14/bits/stl_vector.h:659:23: note:   no known conversion for argument 1 from 'int' to 'std::vector<std::vector<short int, std::allocator<short int> >, std::allocator<std::vector<short int, std::allocator<short int> > > >&&'
  659 |       vector(vector&& __rv, const __type_identity_t<allocator_type>& __m)
      |              ~~~~~~~~~^~~~
/usr/include/c++/14/bits/stl_vector.h:640:7: note: candidate: 'std::vector<_Tp, _Alloc>::vector(std::vector<_Tp, _Alloc>&&, const allocator_type&, std::false_type) [with _Tp = std::vector<short int, std::allocator<short int> >; _Alloc = std::allocator<std::vector<short int, std::allocator<short int> > >; allocator_type = std::allocator<std::vector<short int, std::allocator<short int> > >; std::false_type = std::false_type]'
  640 |       vector(vector&& __rv, const allocator_type& __m, false_type)
      |       ^~~~~~
/usr/include/c++/14/bits/stl_vector.h:640:7: note:   candidate expects 3 arguments, 2 provided
/usr/include/c++/14/bits/stl_vector.h:635:7: note: candidate: 'std::vector<_Tp, _Alloc>::vector(std::vector<_Tp, _Alloc>&&, const allocator_type&, std::true_type) [with _Tp = std::vector<short int, std::allocator<short int> >; _Alloc = std::allocator<std::vector<short int, std::allocator<short int> > >; allocator_type = std::allocator<std::vector<short int, std::allocator<short int> > >; std::true_type = std::true_type]'
  635 |       vector(vector&& __rv, const allocator_type& __m, true_type) noexcept
      |       ^~~~~~
/usr/include/c++/14/bits/stl_vector.h:635:7: note:   candidate expects 3 arguments, 2 provided
/usr/include/c++/14/bits/stl_vector.h:624:7: note: candidate: 'std::vector<_Tp, _Alloc>::vector(const std::vector<_Tp, _Alloc>&, std::__type_identity_t<_Alloc>&) [with _Tp = std::vector<short int, std::allocator<short int> >; _Alloc = std::allocator<std::vector<short int, std::allocator<short int> > >; std::__type_identity_t<_Alloc> = std::allocator<std::vector<short int, std::allocator<short int> > >]'
  624 |       vector(const vector& __x, const __type_identity_t<allocator_type>& __a)
      |       ^~~~~~
/usr/include/c++/14/bits/stl_vector.h:624:28: note:   no known conversion for argument 1 from 'int' to 'const std::vector<std::vector<short int, std::allocator<short int> >, std::allocator<std::vector<short int, std::allocator<short int> > > >&'
  624 |       vector(const vector& __x, const __type_identity_t<allocator_type>& __a)
      |              ~~~~~~~~~~~~~~^~~
/usr/include/c++/14/bits/stl_vector.h:620:7: note: candidate: 'std::vector<_Tp, _Alloc>::vector(std::vector<_Tp, _Alloc>&&) [with _Tp = std::vector<short int, std::allocator<short int> >; _Alloc = std::allocator<std::vector<short int, std::allocator<short int> > >]'
  620 |       vector(vector&&) noexcept = default;
      |       ^~~~~~
/usr/include/c++/14/bits/stl_vector.h:620:7: note:   candidate expects 1 argument, 2 provided
/usr/include/c++/14/bits/stl_vector.h:601:7: note: candidate: 'std::vector<_Tp, _Alloc>::vector(const std::vector<_Tp, _Alloc>&) [with _Tp = std::vector<short int, std::allocator<short int> >; _Alloc = std::allocator<std::vector<short int, std::allocator<short int> > >]'
  601 |       vector(const vector& __x)
      |       ^~~~~~
/usr/include/c++/14/bits/stl_vector.h:601:7: note:   candidate expects 1 argument, 2 provided
/usr/include/c++/14/bits/stl_vector.h:569:7: note: candidate: 'std::vector<_Tp, _Alloc>::vector(size_type, const value_type&, const allocator_type&) [with _Tp = std::vector<short int, std::allocator<short int> >; _Alloc = std::allocator<std::vector<short int, std::allocator<short int> > >; size_type = long unsigned int; value_type = std::vector<short int, std::allocator<short int> >; allocator_type = std::allocator<std::vector<short int, std::allocator<short int> > >]'
  569 |       vector(size_type __n, const value_type& __value,
      |       ^~~~~~
/usr/include/c++/14/bits/stl_vector.h:569:47: note:   no known conversion for argument 2 from 'std::vector<int>' to 'const std::vector<std::vector<short int, std::allocator<short int> >, std::allocator<std::vector<short int, std::allocator<short int> > > >::value_type&' {aka 'const std::vector<short int, std::allocator<short int> >&'}
  569 |       vector(size_type __n, const value_type& __value,
      |                             ~~~~~~~~~~~~~~~~~~^~~~~~~
/usr/include/c++/14/bits/stl_vector.h:556:7: note: candidate: 'std::vector<_Tp, _Alloc>::vector(size_type, const allocator_type&) [with _Tp = std::vector<short int, std::allocator<short int> >; _Alloc = std::allocator<std::vector<short int, std::allocator<short int> > >; size_type = long unsigned int; allocator_type = std::allocator<std::vector<short int, std::allocator<short int> > >]'
  556 |       vector(size_type __n, const allocator_type& __a = allocator_type())
      |       ^~~~~~
/usr/include/c++/14/bits/stl_vector.h:556:51: note:   no known conversion for argument 2 from 'std::vector<int>' to 'const std::vector<std::vector<short int, std::allocator<short int> >, std::allocator<std::vector<short int, std::allocator<short int> > > >::allocator_type&' {aka 'const std::allocator<std::vector<short int, std::allocator<short int> > >&'}
  556 |       vector(size_type __n, const allocator_type& __a = allocator_type())
      |                             ~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/14/bits/stl_vector.h:542:7: note: candidate: 'std::vector<_Tp, _Alloc>::vector(const allocator_type&) [with _Tp = std::vector<short int, std::allocator<short int> >; _Alloc = std::allocator<std::vector<short int, std::allocator<short int> > >; allocator_type = std::allocator<std::vector<short int, std::allocator<short int> > >]'
  542 |       vector(const allocator_type& __a) _GLIBCXX_NOEXCEPT
      |       ^~~~~~
/usr/include/c++/14/bits/stl_vector.h:542:7: note:   candidate expects 1 argument, 2 provided
/usr/include/c++/14/bits/stl_vector.h:531:7: note: candidate: 'std::vector<_Tp, _Alloc>::vector() [with _Tp = std::vector<short int, std::allocator<short int> >; _Alloc = std::allocator<std::vector<short int, std::allocator<short int> > >]'
  531 |       vector() = default;
      |       ^~~~~~
/usr/include/c++/14/bits/stl_vector.h:531:7: note:   candidate expects 0 arguments, 2 provided