Language: C++


#include <iostream>
#include <vector>
#include <algorithm>
#include <queue>

using namespace std;
using ll = long long;

int n;
string s;
const string names="MARCH";
vector<int> checked;

bool checkMarch(int i) {
    if (checked[i]==0) {
        checked[i]=2;
        for (auto c:names) {
            if (s[i]==c) checked[i]=1;
        }
    }
    return checked[i]==1;
}

ll march() {
    sort(s.begin(), s.end(), [](string l, string r) {
        return l < r;
    });
    
    ll ways=0;
    for (auto i=0;i<n-2;i++) {
        auto first=s[i];
        if (!checkMarch(i)) continue;
        for (auto j=i+1;j<n-1;j++) {
            auto second=s[j];
            if (!checkMarch(j)) continue;
            if (first==second) continue;
            for (auto k=j+1;k<n;k++) {
                auto third=s[k];
                if (!checkMarch(k)) continue;
                if (first==third ||
                    second==third) continue;
                ways++;
            }
        }
    }
    
    
    return ways;
}


int main(int argc, const char * argv[]) {
    cin>>n;
    s.assign(n, ' ');
    for (auto &c:s) {
        cin>>c;
    }
    checked.assign(n, 0);
    
    cout<<march();
    
    return 0;
}


Compiler output:
In file included from /usr/include/c++/14/bits/stl_algobase.h:71,
                 from /usr/include/c++/14/string:51,
                 from /usr/include/c++/14/bits/locale_classes.h:40,
                 from /usr/include/c++/14/bits/ios_base.h:41,
                 from /usr/include/c++/14/ios:44,
                 from /usr/include/c++/14/ostream:40,
                 from /usr/include/c++/14/iostream:41,
                 from a.cc:2:
/usr/include/c++/14/bits/predefined_ops.h: In instantiation of 'constexpr bool __gnu_cxx::__ops::_Iter_comp_iter<_Compare>::operator()(_Iterator1, _Iterator2) [with _Iterator1 = __gnu_cxx::__normal_iterator<char*, std::__cxx11::basic_string<char> >; _Iterator2 = __gnu_cxx::__normal_iterator<char*, std::__cxx11::basic_string<char> >; _Compare = march()::<lambda(std::string, std::string)>]':
/usr/include/c++/14/bits/stl_algo.h:1777:14:   required from 'void std::__insertion_sort(_RandomAccessIterator, _RandomAccessIterator, _Compare) [with _RandomAccessIterator = __gnu_cxx::__normal_iterator<char*, __cxx11::basic_string<char> >; _Compare = __gnu_cxx::__ops::_Iter_comp_iter<march()::<lambda(string, string)> >]'
 1777 |           if (__comp(__i, __first))
      |               ~~~~~~^~~~~~~~~~~~~~
/usr/include/c++/14/bits/stl_algo.h:1817:25:   required from 'void std::__final_insertion_sort(_RandomAccessIterator, _RandomAccessIterator, _Compare) [with _RandomAccessIterator = __gnu_cxx::__normal_iterator<char*, __cxx11::basic_string<char> >; _Compare = __gnu_cxx::__ops::_Iter_comp_iter<march()::<lambda(string, string)> >]'
 1817 |           std::__insertion_sort(__first, __first + int(_S_threshold), __comp);
      |           ~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/14/bits/stl_algo.h:1908:31:   required from 'void std::__sort(_RandomAccessIterator, _RandomAccessIterator, _Compare) [with _RandomAccessIterator = __gnu_cxx::__normal_iterator<char*, __cxx11::basic_string<char> >; _Compare = __gnu_cxx::__ops::_Iter_comp_iter<march()::<lambda(string, string)> >]'
 1908 |           std::__final_insertion_sort(__first, __last, __comp);
      |           ~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/14/bits/stl_algo.h:4805:18:   required from 'void std::sort(_RAIter, _RAIter, _Compare) [with _RAIter = __gnu_cxx::__normal_iterator<char*, __cxx11::basic_string<char> >; _Compare = march()::<lambda(string, string)>]'
 4805 |       std::__sort(__first, __last, __gnu_cxx::__ops::__iter_comp_iter(__comp));
      |       ~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
a.cc:26:9:   required from here
   26 |     sort(s.begin(), s.end(), [](string l, string r) {
      |     ~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   27 |         return l < r;
      |         ~~~~~~~~~~~~~
   28 |     });
      |     ~~   
/usr/include/c++/14/bits/predefined_ops.h:158:30: error: no match for call to '(march()::<lambda(std::string, std::string)>) (char&, char&)'
  158 |         { return bool(_M_comp(*__it1, *__it2)); }
      |                       ~~~~~~~^~~~~~~~~~~~~~~~
/usr/include/c++/14/bits/predefined_ops.h:158:30: note: candidate: 'bool (*)(std::string, std::string)' {aka 'bool (*)(std::__cxx11::basic_string<char>, std::__cxx11::basic_string<char>)'} (conversion)
/usr/include/c++/14/bits/predefined_ops.h:158:30: note:   candidate expects 3 arguments, 3 provided
a.cc:26:30: note: candidate: 'march()::<lambda(std::string, std::string)>'
   26 |     sort(s.begin(), s.end(), [](string l, string r) {
      |                              ^
a.cc:26:30: note:   no known conversion for argument 1 from 'char' to 'std::string' {aka 'std::__cxx11::basic_string<char>'}
/usr/include/c++/14/bits/predefined_ops.h: In instantiation of 'bool __gnu_cxx::__ops::_Val_comp_iter<_Compare>::operator()(_Value&, _Iterator) [with _Value = char; _Iterator = __gnu_cxx::__normal_iterator<char*, std::__cxx11::basic_string<char> >; _Compare = march()::<lambda(std::string, std::string)>]':
/usr/include/c++/14/bits/stl_algo.h:1757:20:   required from 'void std::__unguarded_linear_insert(_RandomAccessIterator, _Compare) [with _RandomAccessIterator = __gnu_cxx::__normal_iterator<char*, __cxx11::basic_string<char> >; _Compare = __gnu_cxx::__ops::_Val_comp_iter<march()::<lambda(string, string)> >]'
 1757 |       while (__comp(__val, __next))
      |              ~~~~~~^~~~~~~~~~~~~~~
/usr/include/c++/14/bits/stl_algo.h:1785:36:   required from 'void std::__insertion_sort(_RandomAccessIterator, _RandomAccessIterator, _Compare) [with _RandomAccessIterator = __gnu_cxx::__normal_iterator<char*, __cxx11::basic_string<char> >; _Compare = __gnu_cxx::__ops::_Iter_comp_iter<march()::<lambda(string, string)> >]'
 1785 |             std::__unguarded_linear_insert(__i,
      |             ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~
 1786 |                                 __gnu_cxx::__ops::__val_comp_iter(__comp));
      |                                 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/14/bits/stl_algo.h:1817:25:   required from 'void std::__final_insertion_sort(_RandomAccessIterator, _RandomAccessIterator, _Compare) [with _RandomAccessIterator = __gnu_cxx::__normal_iterator<char*, __cxx11::basic_string<char> >; _Compare = __gnu_cxx::__ops::_Iter_comp_iter<march()::<lambda(string, string)> >]'
 1817 |           std::__insertion_sort(__first, __first + int(_S_threshold), __comp);
      |           ~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/14/bits/stl_algo.h:1908:31:   required from 'void std::__sort(_RandomAccessIterator, _RandomAccessIterator, _Compare) [with _RandomAccessIterator = __gnu_cxx::__normal_iterator<char*, __cxx11::basic_string<char> >; _Compare = __gnu_cxx::__ops::_Iter_comp_iter<march()::<lambda(string, string)> >]'
 1908 |           std::__final_insertion_sort(__first, __last, __comp);
      |           ~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/14/bits/stl_algo.h:4805:18:   required from 'void std::sort(_RAIter, _RAIter, _Compare) [with _RAIter = __gnu_cxx::__normal_iterator<char*, __cxx11::basic_string<char> >; _Compare = march()::<lambda(string, string)>]'
 4805 |       std::__sort(__first, __last, __gnu_cxx::__ops::__iter_comp_iter(__comp));
      |       ~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
a.cc:26:9:   required from here
   26 |     sort(s.begin(), s.end(), [](string l, string r) {
      |     ~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   27 |         return l < r;
      |         ~~~~~~~~~~~~~
   28 |     });
      |     ~~   
/usr/include/c++/14/bits/predefined_ops.h:240:30: error: no match for call to '(march()::<lambda(std::string, std::string)>) (char&, char&)'
  240 |         { return bool(_M_comp(__val, *__it)); }
      |                       ~~~~~~~^~~~~~~~~~~~~~
/usr/include/c++/14/bits/predefined_ops.h:240:30: note: candidate: 'bool (*)(std::string, std::string)' {aka 'bool (*)(std::__cxx11::basic_string<char>, std::__cxx11::basic_string<char>)'} (conversion)
/usr/include/c++/14/bits/predefined_ops.h:240:30: note:   candidate expects 3 arguments, 3 provided
a.cc:26:30: note: candidate: 'march()::<lambda(std::string, std::string)>'
   26 |     sort(s.begin(), s.end(), [](string l, string r) {
      |                              ^
a.cc:26:30: note:   no known conversion for argument 1 from 'char' to 'std::string' {aka 'std::__cxx11::basic_string<char>'}
/usr/include/c++/14/bits/predefined_ops.h: In instantiation of 'bool __gnu_cxx::__ops::_Iter_comp_val<_Compare>::operator()(_Iterator, _Value&) [with _Iterator = __gnu_cxx::__normal_iterator<char*, std::__cxx11::basic_string<char> >; _Value = char; _Compare = march()::<lambda(std::string, std::string)>]':
/usr/include/c++/14/bits/stl_heap.h:140:48:   required from 'void std::__push_heap(_RandomAccessIterator, _Distance, _Distance, _Tp, _Compare&) [with _RandomAccessIterator = __gnu_cxx::__normal_iterator<char*, __cxx11::basic_string<char> >; _Distance = long int; _Tp = char; _Compare = __gnu_cxx::__ops::_Iter_comp_val<march()::<lambda(string, string)> >]'
  140 |       while (__holeIndex > __topIndex && __comp(__first + __parent, __value))
      |                                          ~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/14/bits/stl_heap.h:247:23:   required from 'void std::__adjust_heap(_RandomAccessIterator, _Distance, _Distance, _Tp, _Compare) [with _RandomAccessIterator = __gnu_cxx::__normal_iterator<char*, __cxx11::basic_string<char> >; _Distance = long int; _Tp = char; _Compare = __gnu_cxx::__ops::_Iter_comp_iter<march()::<lambda(string, string)> >]'
  247 |       std::__push_heap(__first, __holeIndex, __topIndex,
      |       ~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  248 |                        _GLIBCXX_MOVE(__value), __cmp);
      |                        ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/14/bits/stl_heap.h:356:22:   required from 'void std::__make_heap(_RandomAccessIterator, _RandomAccessIterator, _Compare&) [with _RandomAccessIterator = __gnu_cxx::__normal_iterator<char*, __cxx11::basic_string<char> >; _Compare = __gnu_cxx::__ops::_Iter_comp_iter<march()::<lambda(string, string)> >]'
  356 |           std::__adjust_heap(__first, __parent, __len, _GLIBCXX_MOVE(__value),
      |           ~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  357 |                              __comp);
      |                              ~~~~~~~
/usr/include/c++/14/bits/stl_algo.h:1593:23:   required from 'void std::__heap_select(_RandomAccessIterator, _RandomAccessIterator, _RandomAccessIterator, _Compare) [with _RandomAccessIterator = __gnu_cxx::__normal_iterator<char*, __cxx11::basic_string<char> >; _Compare = __gnu_cxx::__ops::_Iter_comp_iter<march()::<lambda(string, string)> >]'
 1593 |       std::__make_heap(__first, __middle, __comp);
      |       ~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/14/bits/stl_algo.h:1868:25:   required from 'void std::__partial_sort(_RandomAccessIterator, _RandomAccessIterator, _RandomAccessIterator, _Compare) [with _RandomAccessIterator = __gnu_cxx::__normal_iterator<char*, __cxx11::b