Language: C++

#include <bits/stdc++.h>
using namespace std;
#define rep(i,n) for(int i = 0; i < (n);i++)
#define sz(x) int(x.size())
typedef long long ll;
typedef pair<int,int> P;

int main(){
  ll k; 
  string s;
  cin >> s >> k;
  string t = s;
  s += '#';
  int n = sz(s);
  ll cnt1 = 0;
  map<int,int> mp1;
  int prev = 0;
  for (int i = 0; i < n; i++) {
    if (s[prev] != s[i]]) {
      mp1[prev] = i - prev;
      prev = i;
    }
  }
  for (auto e : mp1) cnt1 += e / 2;
  t += s;
  ll cnt2 = 0;
  int m = sz(t);
  map<int,int> mp2;
  prev = 0;
  for (int i = 0; i < m; i++) {
    if (t[prev] != t[i]) {
      mp2[prev] = i - prev;
      prev = i;
    }
  }
  for (auto e : mp2) cnt2 += e / 2;

  ll dif = cnt2 - cnt1 * 2;
  cout << k * cnt1 + (k-1) * dif << endl; 
  return 0;
} 

Compiler output:
a.cc: In function 'int main()':
a.cc:19:24: error: expected ')' before ']' token
   19 |     if (s[prev] != s[i]]) {
      |        ~               ^
      |                        )
a.cc:19:24: error: expected primary-expression before ']' token
a.cc:24:32: error: no match for 'operator/' (operand types are 'std::pair<const int, int>' and 'int')
   24 |   for (auto e : mp1) cnt1 += e / 2;
      |                              ~ ^ ~
      |                              |   |
      |                              |   int
      |                              std::pair<const int, int>
In file included from /usr/include/c++/14/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/14/bits/stdc++.h:127,
                 from a.cc:1:
/usr/include/c++/14/complex:430:5: note: candidate: 'template<class _Tp> std::complex<_Tp> std::operator/(const complex<_Tp>&, const complex<_Tp>&)'
  430 |     operator/(const complex<_Tp>& __x, const complex<_Tp>& __y)
      |     ^~~~~~~~
/usr/include/c++/14/complex:430:5: note:   template argument deduction/substitution failed:
a.cc:24:34: note:   'std::pair<const int, int>' is not derived from 'const std::complex<_Tp>'
   24 |   for (auto e : mp1) cnt1 += e / 2;
      |                                  ^
/usr/include/c++/14/complex:439:5: note: candidate: 'template<class _Tp> std::complex<_Tp> std::operator/(const complex<_Tp>&, const _Tp&)'
  439 |     operator/(const complex<_Tp>& __x, const _Tp& __y)
      |     ^~~~~~~~
/usr/include/c++/14/complex:439:5: note:   template argument deduction/substitution failed:
a.cc:24:34: note:   'std::pair<const int, int>' is not derived from 'const std::complex<_Tp>'
   24 |   for (auto e : mp1) cnt1 += e / 2;
      |                                  ^
/usr/include/c++/14/complex:448:5: note: candidate: 'template<class _Tp> std::complex<_Tp> std::operator/(const _Tp&, const complex<_Tp>&)'
  448 |     operator/(const _Tp& __x, const complex<_Tp>& __y)
      |     ^~~~~~~~
/usr/include/c++/14/complex:448:5: note:   template argument deduction/substitution failed:
a.cc:24:34: note:   mismatched types 'const std::complex<_Tp>' and 'int'
   24 |   for (auto e : mp1) cnt1 += e / 2;
      |                                  ^
In file included from /usr/include/c++/14/valarray:605,
                 from /usr/include/x86_64-linux-gnu/c++/14/bits/stdc++.h:166:
/usr/include/c++/14/bits/valarray_after.h:408:5: note: candidate: 'template<class _Dom1, class _Dom2> std::_Expr<std::__detail::_BinClos<std::__divides, std::_Expr, std::_Expr, _Dom1, _Dom2>, typename std::__fun<std::__divides, typename _Dom1::value_type>::result_type> std::operator/(const _Expr<_Dom1, typename _Dom1::value_type>&, const _Expr<_Dom2, typename _Dom2::value_type>&)'
  408 |     _DEFINE_EXPR_BINARY_OPERATOR(/, struct std::__divides)
      |     ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/14/bits/valarray_after.h:408:5: note:   template argument deduction/substitution failed:
a.cc:24:34: note:   'std::pair<const int, int>' is not derived from 'const std::_Expr<_Dom1, typename _Dom1::value_type>'
   24 |   for (auto e : mp1) cnt1 += e / 2;
      |                                  ^
/usr/include/c++/14/bits/valarray_after.h:408:5: note: candidate: 'template<class _Dom> std::_Expr<std::__detail::_BinClos<std::__divides, std::_Expr, std::_Constant, _Dom, typename _Dom::value_type>, typename std::__fun<std::__divides, typename _Dom1::value_type>::result_type> std::operator/(const _Expr<_Dom1, typename _Dom1::value_type>&, const typename _Dom::value_type&)'
  408 |     _DEFINE_EXPR_BINARY_OPERATOR(/, struct std::__divides)
      |     ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/14/bits/valarray_after.h:408:5: note:   template argument deduction/substitution failed:
a.cc:24:34: note:   'std::pair<const int, int>' is not derived from 'const std::_Expr<_Dom1, typename _Dom1::value_type>'
   24 |   for (auto e : mp1) cnt1 += e / 2;
      |                                  ^
/usr/include/c++/14/bits/valarray_after.h:408:5: note: candidate: 'template<class _Dom> std::_Expr<std::__detail::_BinClos<std::__divides, std::_Constant, std::_Expr, typename _Dom::value_type, _Dom>, typename std::__fun<std::__divides, typename _Dom1::value_type>::result_type> std::operator/(const typename _Dom::value_type&, const _Expr<_Dom1, typename _Dom1::value_type>&)'
  408 |     _DEFINE_EXPR_BINARY_OPERATOR(/, struct std::__divides)
      |     ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/14/bits/valarray_after.h:408:5: note:   template argument deduction/substitution failed:
a.cc:24:34: note:   mismatched types 'const std::_Expr<_Dom1, typename _Dom1::value_type>' and 'int'
   24 |   for (auto e : mp1) cnt1 += e / 2;
      |                                  ^
/usr/include/c++/14/bits/valarray_after.h:408:5: note: candidate: 'template<class _Dom> std::_Expr<std::__detail::_BinClos<std::__divides, std::_Expr, std::_ValArray, _Dom, typename _Dom::value_type>, typename std::__fun<std::__divides, typename _Dom1::value_type>::result_type> std::operator/(const _Expr<_Dom1, typename _Dom1::value_type>&, const valarray<typename _Dom::value_type>&)'
  408 |     _DEFINE_EXPR_BINARY_OPERATOR(/, struct std::__divides)
      |     ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/14/bits/valarray_after.h:408:5: note:   template argument deduction/substitution failed:
a.cc:24:34: note:   'std::pair<const int, int>' is not derived from 'const std::_Expr<_Dom1, typename _Dom1::value_type>'
   24 |   for (auto e : mp1) cnt1 += e / 2;
      |                                  ^
/usr/include/c++/14/bits/valarray_after.h:408:5: note: candidate: 'template<class _Dom> std::_Expr<std::__detail::_BinClos<std::__divides, std::_ValArray, std::_Expr, typename _Dom::value_type, _Dom>, typename std::__fun<std::__divides, typename _Dom1::value_type>::result_type> std::operator/(const valarray<typename _Dom::value_type>&, const _Expr<_Dom1, typename _Dom1::value_type>&)'
  408 |     _DEFINE_EXPR_BINARY_OPERATOR(/, struct std::__divides)
      |     ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/14/bits/valarray_after.h:408:5: note:   template argument deduction/substitution failed:
a.cc:24:34: note:   mismatched types 'const std::_Expr<_Dom1, typename _Dom1::value_type>' and 'int'
   24 |   for (auto e : mp1) cnt1 += e / 2;
      |                                  ^
/usr/include/c++/14/valarray:1199:1: note: candidate: 'template<class _Tp> std::_Expr<std::__detail::_BinClos<std::__divides, std::_ValArray, std::_ValArray, _Tp, _Tp>, typename std::__fun<std::__divides, _Tp>::result_type> std::operator/(const valarray<_Tp>&, const valarray<_Tp>&)'
 1199 | _DEFINE_BINARY_OPERATOR(/, __divides)
      | ^~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/14/valarray:1199:1: note:   template argument deduction/substitution failed:
a.cc:24:34: note:   'std::pair<const int, int>' is not derived from 'const std::valarray<_Tp>'
   24 |   for (auto e : mp1) cnt1 += e / 2;
      |                                  ^
/usr/include/c++/14/valarray:1199:1: note: candidate: 'template<class _Tp> std::_Expr<std::__detail::_BinClos<std::__divides, std::_ValArray, std::_Constant, _Tp, _Tp>, typename std::__fun<std::__divides, _Tp>::result_type> std::operator/(const valarray<_Tp>&, const typename valarray<_Tp>::value_type&)'
 1199 | _DEFINE_BINARY_OPERATOR(/, __divides)
      | ^~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/14/valarray:1199:1: note:   template argument deduction/substitution failed:
a.cc:24:34: note:   'std::pair<const int, int>' is not derived from 'const std::valarray<_Tp>'
   24 |   for (auto e : mp1) cnt1 += e / 2;
      |                                  ^
/usr/include/c++/14/valarray:1199:1: note: candidate: 'template<class _Tp> std::_Expr<std::__detail::_BinClos<std::__divides, std::_Constant, std::_ValArray, _Tp, _Tp>, typename std::__fun<std::__divides, _Tp>::result_type> std::operator/(const typename valarray<_Tp>::value_type&, const valarray<_Tp>&)'
 1199 | _DEFINE_BINARY_OPERATOR(/, __divides)
      | ^~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/14/valarray:1199:1: note:   template argument deduction/substitution failed:
a.cc:24:34: note:   mismatched types 'const std::valarray<_Tp>' and 'int'
   24 |   for (auto e : mp1) cnt1 += e / 2;
      |                                  ^
a.cc:36:32: error: no match for 'operator/' (operand types are 'std::pair<const int, int>' and 'int')
   36 |   for (auto e : mp2) cnt2 += e / 2;
      |                              ~ ^ ~
      |                              |   |
      |                              |   int
      |                              std::pair<const int, int>
/usr/include/c++/14/complex:430:5: note: candidate: 'template<class _Tp> std::complex<_Tp> std::operator/(const complex<_Tp>&, const complex<_Tp>&)'
  430 |     operator/(const complex<_Tp>& __x, const complex<_Tp>& __y)
      |     ^~~~~~~~
/usr/include/c++/14/complex:430:5: note:   template argument deduction/substitution failed:
a.cc:36:34: note:   'std::pair<const int, int>' is not derived from 'const std::complex<_Tp>'
   36 |   for (auto e : mp2) cnt2 += e / 2;
      |                                  ^
/usr/include/c++/14/complex:439:5: note: candidate: 'template<class _Tp> std::complex<_Tp> std::operator/(const complex<_Tp>&, const _Tp&)'
  439 |     operator/(const complex<_Tp>& __x, const _Tp& __y)
      |     ^~~~~~~~
/usr/include/c++/14/complex:439:5: note:   template argument deduction/substitution failed:
a.cc:36:34: note:   'std::pair<const int, int>' is not derived from 'const std::complex<_Tp>'
   36 |   for (auto e : mp2) cnt2 += e / 2;
      |                                  ^
/usr/include/c++/14/complex:448:5: note: candidate: 'template<class _Tp> std::complex<_Tp> std::operator/(const _Tp&, const complex<_Tp>&)'
  448 |     operator/(const _Tp& __x, const complex<_Tp>& __y)
      |     ^~~~~~~~
/usr/include/c++/14/complex:448:5: note:   template argument deduction/substitution failed:
a.cc:36:34: note:   mismatched types 'const std::complex<_Tp>' and 'int'
   36 |   for (auto e : mp2) cnt2 += e / 2;
      |                                  ^
/usr/include/c++/14/bits/valarray_after.h:408:5: note: candidate: 'template<class _Dom1, class _Dom2> std::_Expr<std: