Language: C++

#include <bits/stdc++.h>
#define _GLIBCXX_DEBUG
using namespace std;
using ll=long long;
using vec=vector<ll>;
using Graph = vector<vector<ll>>;
#define loop(i,n) for(ll i=0;i<n;i++)
#define Loop(i, m, n) for(ll i = m;i < n;i++)
#define pool(i,n) for(ll i=n;i>=0;i--)
#define Pool(i, m, n) for(ll i=n;i>=m;i--)
#define MAX 99999999999ll
#define MIN -99999999999ll
#define setbit bitset<8>
#define flagcount __builtin_popcount
#define flag(x) (1<<x)
#define flagadd(bit,x) bit|=flag(x)
#define flagpop(bit,x) bit&=~flag(x) 
#define flagon(bit,i) bit&flag(i)
#define flagoff(bit,i) !(bit & (1<<i))
#define all(v) v.begin(),v.end()
#define low2way(v,x) lower_bound(all(v),x)
#define high2way(v,x) upper_bound(all(v),x)
#define count2way(v,x) high2way(v,x)-low2way(v,x)
#define lower(v,x) low2way(v,x)-v.begin() //1番左が0、もし見つから無いならｎを出力
#define higher(v,x) high2way(v,x)-v.begin()-1 //1番左が0、もし見つからないならn-1を出力（注意）
#define putout(a) cout<<a<<endl
#define putout2(a,b) putout(a);putout(b)
#define putout3(a,b,c) putout(a);putout(b);putout(c)
#define putout4(a,b,c,d) putout(a);putout(b);putout(c);putout(d)
#define putout5(a,b,c,d,e) putout(a);putout(b);putout(c);putout(d);putout(e)
#define Gput(a,b) G[a].push_back(b)
#define cin1(a) cin>>a
#define cin2(a,b) cin>>a>>b
#define cin3(a,b,c) cin>>a>>b>>c
#define cin4(a,b,c,d) cin>>a>>b>>c>>d
#define cin5(a,b,c,d,e) cin>>a>>b>>c>>d>>e
#define sum(v) accumulate(all(v), 0ll)
#define gcd(x,y) __gcd(x,y)
ll ctoi(char c){
	if(c>='0'&&c<='9'){
		return c-'0';
	}
	return 0;
}
ll lcm(ll x,ll y){
  ll z=gcd(x,y);
  return x*y/z;
}
int main() {
cout << fixed << setprecision(30);
  string s;
  cin>>s;
  if(s=='SUN')putout(7);
  if(s=='MON')putout(6);
  if(s=='TUE')putout(5);
  if(s=='WED')putout(4);
  if(s=='THU')putout(3);
  if(s=='FRI')putout(2);
  if(s=='SAT')putout(1);
}

Compiler output:
a.cc:53:9: warning: multi-character character constant [-Wmultichar]
   53 |   if(s=='SUN')putout(7);
      |         ^~~~~
a.cc:54:9: warning: multi-character character constant [-Wmultichar]
   54 |   if(s=='MON')putout(6);
      |         ^~~~~
a.cc:55:9: warning: multi-character character constant [-Wmultichar]
   55 |   if(s=='TUE')putout(5);
      |         ^~~~~
a.cc:56:9: warning: multi-character character constant [-Wmultichar]
   56 |   if(s=='WED')putout(4);
      |         ^~~~~
a.cc:57:9: warning: multi-character character constant [-Wmultichar]
   57 |   if(s=='THU')putout(3);
      |         ^~~~~
a.cc:58:9: warning: multi-character character constant [-Wmultichar]
   58 |   if(s=='FRI')putout(2);
      |         ^~~~~
a.cc:59:9: warning: multi-character character constant [-Wmultichar]
   59 |   if(s=='SAT')putout(1);
      |         ^~~~~
a.cc: In function 'int main()':
a.cc:53:7: error: no match for 'operator==' (operand types are 'std::string' {aka 'std::__cxx11::basic_string<char>'} and 'int')
   53 |   if(s=='SUN')putout(7);
      |      ~^~~~~~~
      |      |  |
      |      |  int
      |      std::string {aka std::__cxx11::basic_string<char>}
In file included from /usr/include/c++/14/regex:68,
                 from /usr/include/x86_64-linux-gnu/c++/14/bits/stdc++.h:181,
                 from a.cc:1:
/usr/include/c++/14/bits/regex.h:1103:5: note: candidate: 'template<class _BiIter> bool std::__cxx11::operator==(const sub_match<_BiIter>&, const sub_match<_BiIter>&)'
 1103 |     operator==(const sub_match<_BiIter>& __lhs, const sub_match<_BiIter>& __rhs)
      |     ^~~~~~~~
/usr/include/c++/14/bits/regex.h:1103:5: note:   template argument deduction/substitution failed:
a.cc:53:9: note:   'std::string' {aka 'std::__cxx11::basic_string<char>'} is not derived from 'const std::__cxx11::sub_match<_BiIter>'
   53 |   if(s=='SUN')putout(7);
      |         ^~~~~
/usr/include/c++/14/bits/regex.h:1199:5: note: candidate: 'template<class _Bi_iter, class _Ch_traits, class _Ch_alloc> bool std::__cxx11::operator==(__sub_match_string<_Bi_iter, _Ch_traits, _Ch_alloc>&, const sub_match<_BiIter>&)'
 1199 |     operator==(const __sub_match_string<_Bi_iter, _Ch_traits, _Ch_alloc>& __lhs,
      |     ^~~~~~~~
/usr/include/c++/14/bits/regex.h:1199:5: note:   template argument deduction/substitution failed:
a.cc:53:9: note:   mismatched types 'const std::__cxx11::sub_match<_BiIter>' and 'int'
   53 |   if(s=='SUN')putout(7);
      |         ^~~~~
/usr/include/c++/14/bits/regex.h:1274:5: note: candidate: 'template<class _Bi_iter, class _Ch_traits, class _Ch_alloc> bool std::__cxx11::operator==(const sub_match<_BiIter>&, __sub_match_string<_Bi_iter, _Ch_traits, _Ch_alloc>&)'
 1274 |     operator==(const sub_match<_Bi_iter>& __lhs,
      |     ^~~~~~~~
/usr/include/c++/14/bits/regex.h:1274:5: note:   template argument deduction/substitution failed:
a.cc:53:9: note:   'std::string' {aka 'std::__cxx11::basic_string<char>'} is not derived from 'const std::__cxx11::sub_match<_BiIter>'
   53 |   if(s=='SUN')putout(7);
      |         ^~~~~
/usr/include/c++/14/bits/regex.h:1366:5: note: candidate: 'template<class _Bi_iter> bool std::__cxx11::operator==(const typename std::iterator_traits<_Iter>::value_type*, const sub_match<_BiIter>&)'
 1366 |     operator==(typename iterator_traits<_Bi_iter>::value_type const* __lhs,
      |     ^~~~~~~~
/usr/include/c++/14/bits/regex.h:1366:5: note:   template argument deduction/substitution failed:
a.cc:53:9: note:   mismatched types 'const std::__cxx11::sub_match<_BiIter>' and 'int'
   53 |   if(s=='SUN')putout(7);
      |         ^~~~~
/usr/include/c++/14/bits/regex.h:1441:5: note: candidate: 'template<class _Bi_iter> bool std::__cxx11::operator==(const sub_match<_BiIter>&, const typename std::iterator_traits<_Iter>::value_type*)'
 1441 |     operator==(const sub_match<_Bi_iter>& __lhs,
      |     ^~~~~~~~
/usr/include/c++/14/bits/regex.h:1441:5: note:   template argument deduction/substitution failed:
a.cc:53:9: note:   'std::string' {aka 'std::__cxx11::basic_string<char>'} is not derived from 'const std::__cxx11::sub_match<_BiIter>'
   53 |   if(s=='SUN')putout(7);
      |         ^~~~~
/usr/include/c++/14/bits/regex.h:1534:5: note: candidate: 'template<class _Bi_iter> bool std::__cxx11::operator==(const typename std::iterator_traits<_Iter>::value_type&, const sub_match<_BiIter>&)'
 1534 |     operator==(typename iterator_traits<_Bi_iter>::value_type const& __lhs,
      |     ^~~~~~~~
/usr/include/c++/14/bits/regex.h:1534:5: note:   template argument deduction/substitution failed:
a.cc:53:9: note:   mismatched types 'const std::__cxx11::sub_match<_BiIter>' and 'int'
   53 |   if(s=='SUN')putout(7);
      |         ^~~~~
/usr/include/c++/14/bits/regex.h:1613:5: note: candidate: 'template<class _Bi_iter> bool std::__cxx11::operator==(const sub_match<_BiIter>&, const typename std::iterator_traits<_Iter>::value_type&)'
 1613 |     operator==(const sub_match<_Bi_iter>& __lhs,
      |     ^~~~~~~~
/usr/include/c++/14/bits/regex.h:1613:5: note:   template argument deduction/substitution failed:
a.cc:53:9: note:   'std::string' {aka 'std::__cxx11::basic_string<char>'} is not derived from 'const std::__cxx11::sub_match<_BiIter>'
   53 |   if(s=='SUN')putout(7);
      |         ^~~~~
/usr/include/c++/14/bits/regex.h:2186:5: note: candidate: 'template<class _Bi_iter, class _Alloc> bool std::__cxx11::operator==(const match_results<_BiIter, _Alloc>&, const match_results<_BiIter, _Alloc>&)'
 2186 |     operator==(const match_results<_Bi_iter, _Alloc>& __m1,
      |     ^~~~~~~~
/usr/include/c++/14/bits/regex.h:2186:5: note:   template argument deduction/substitution failed:
a.cc:53:9: note:   'std::string' {aka 'std::__cxx11::basic_string<char>'} is not derived from 'const std::__cxx11::match_results<_BiIter, _Alloc>'
   53 |   if(s=='SUN')putout(7);
      |         ^~~~~
In file included from /usr/include/c++/14/bits/stl_algobase.h:64,
                 from /usr/include/c++/14/algorithm:60,
                 from /usr/include/x86_64-linux-gnu/c++/14/bits/stdc++.h:51:
/usr/include/c++/14/bits/stl_pair.h:1033:5: note: candidate: 'template<class _T1, class _T2> constexpr bool std::operator==(const pair<_T1, _T2>&, const pair<_T1, _T2>&)'
 1033 |     operator==(const pair<_T1, _T2>& __x, const pair<_T1, _T2>& __y)
      |     ^~~~~~~~
/usr/include/c++/14/bits/stl_pair.h:1033:5: note:   template argument deduction/substitution failed:
a.cc:53:9: note:   'std::string' {aka 'std::__cxx11::basic_string<char>'} is not derived from 'const std::pair<_T1, _T2>'
   53 |   if(s=='SUN')putout(7);
      |         ^~~~~
In file included from /usr/include/c++/14/bits/stl_algobase.h:67:
/usr/include/c++/14/bits/stl_iterator.h:441:5: note: candidate: 'template<class _Iterator> constexpr bool std::operator==(const reverse_iterator<_Iterator>&, const reverse_iterator<_Iterator>&)'
  441 |     operator==(const reverse_iterator<_Iterator>& __x,
      |     ^~~~~~~~
/usr/include/c++/14/bits/stl_iterator.h:441:5: note:   template argument deduction/substitution failed:
a.cc:53:9: note:   'std::string' {aka 'std::__cxx11::basic_string<char>'} is not derived from 'const std::reverse_iterator<_Iterator>'
   53 |   if(s=='SUN')putout(7);
      |         ^~~~~
/usr/include/c++/14/bits/stl_iterator.h:486:5: note: candidate: 'template<class _IteratorL, class _IteratorR> constexpr bool std::operator==(const reverse_iterator<_Iterator>&, const reverse_iterator<_IteratorR>&)'
  486 |     operator==(const reverse_iterator<_IteratorL>& __x,
      |     ^~~~~~~~
/usr/include/c++/14/bits/stl_iterator.h:486:5: note:   template argument deduction/substitution failed:
a.cc:53:9: note:   'std::string' {aka 'std::__cxx11::basic_string<char>'} is not derived from 'const std::reverse_iterator<_Iterator>'
   53 |   if(s=='SUN')putout(7);
      |         ^~~~~
/usr/include/c++/14/bits/stl_iterator.h:1667:5: note: candidate: 'template<class _IteratorL, class _IteratorR> constexpr bool std::operator==(const move_iterator<_IteratorL>&, const move_iterator<_IteratorR>&)'
 1667 |     operator==(const move_iterator<_IteratorL>& __x,
      |     ^~~~~~~~
/usr/include/c++/14/bits/stl_iterator.h:1667:5: note:   template argument deduction/substitution failed:
a.cc:53:9: note:   'std::string' {aka 'std::__cxx11::basic_string<char>'} is not derived from 'const std::move_iterator<_IteratorL>'
   53 |   if(s=='SUN')putout(7);
      |         ^~~~~
/usr/include/c++/14/bits/stl_iterator.h:1737:5: note: candidate: 'template<class _Iterator> constexpr bool std::operator==(const move_iterator<_IteratorL>&, const move_iterator<_IteratorL>&)'
 1737 |     operator==(const move_iterator<_Iterator>& __x,
      |     ^~~~~~~~
/usr/include/c++/14/bits/stl_iterator.h:1737:5: note:   template argument deduction/substitution failed:
a.cc:53:9: note:   'std::string' {aka 'std::__cxx11::basic_string<char>'} is not derived from 'const std::move_iterator<_IteratorL>'
   53 |   if(s=='SUN')putout(7);
      |         ^~~~~
In file included from /usr/include/c++/14/bits/char_traits.h:42,
                 from /usr/include/c++/14/string:42,
                 from /usr/include/c++/14/bitset:52,
                 from /usr/include/x86_64-linux-gnu/c++/14/bits/stdc++.h:52:
/usr/include/c++/14/bits/postypes.h:192:5: note: candidate: 'template<class _StateT> bool std::operator==(const fpos<_StateT>&, const fpos<_StateT>&)'
  192 |     operator==(const fpos<_StateT>& __lhs, const fpos<_StateT>& __rhs)
      |     ^~~~~~~~
/usr/include/c++/14/bits/postypes.h:192:5: note:   template argument deduction/substitution failed:
a.cc:53:9: note:   'std::string' {aka 'std::__cxx11::basic_string<char>'} is not derived from 'const std::fpos<_StateT>'
   53 |   if(s=='SUN')putout(7);
      |         ^~~~~
In file included from /usr/include/c++/14/string:43:
/usr/include/c++/14/bits/allocator.h:235:5: note: candidate: 'template<class _T1, class _T2> bool std::operator==(const allocator<_CharT>&, const allocator<_T2>&)'
  235 |     operator==(const allocator<_T1>&, const allocator<_T2>&)
      |     ^~~~~~~~
/usr/include/c++/14/bits/allocator.h:235:5: note:   template argument deduction/substitution failed:
a.cc:53:9: note:   'std