Language: C++

#include <bits/stdc++.h>

using namespace std;

#define ll long long
#define ull unsigned long long
#define PI acos(-1.0)
#define eps 1e-12
#define fi first
#define se second
#define MEM(a,b) memset((a),(b),sizeof(a))
#define mod(x) ((x)%MOD)
#define pii pair

const int maxn = 4e5 + 10, INF = 0x3f3f3f3f;
const ll MOD = 1000000007LL;
const int Move[4][2] = {-1,0,1,0,0,1,0,-1};
const int Move_[8][2] = {-1,-1,-1,0,-1,1,0,-1,0,1,1,-1,1,0,1,1};

inline int read(){
int x=0,f=1;char ch=getchar();
while(ch<'0'||ch>'9'){if(ch=='-')f=-1;ch=getchar();}
while(ch>='0'&&ch<='9'){x=x10+ch-'0';ch=getchar();} return xf;
}

map m;

int main(){
// freopen("C:\Users\Administrator\Desktop\in.txt","r",stdin);
// freopen("C:\Users\Administrator\Desktop\out.txt","w",stdout);
ull a,b,c,k;
cin>>a>>b>>c>>k;
ll res;
if (k & 1) {
cout<<b - a<<endl;
} else cout<<a - b<<endl;
return 0;
}


Compiler output:
a.cc: In function 'int read()':
a.cc:23:27: error: 'x10' was not declared in this scope
   23 | while(ch>='0'&&ch<='9'){x=x10+ch-'0';ch=getchar();} return xf;
      |                           ^~~
a.cc:23:60: error: 'xf' was not declared in this scope; did you mean 'f'?
   23 | while(ch>='0'&&ch<='9'){x=x10+ch-'0';ch=getchar();} return xf;
      |                                                            ^~
      |                                                            f
a.cc: At global scope:
a.cc:26:5: error: class template argument deduction failed:
   26 | map m;
      |     ^
a.cc:26:5: error: no matching function for call to 'map()'
In file included from /usr/include/c++/14/map:63,
                 from /usr/include/x86_64-linux-gnu/c++/14/bits/stdc++.h:152,
                 from a.cc:1:
/usr/include/c++/14/bits/stl_map.h:302:9: note: candidate: 'template<class _Key, class _Tp, class _Compare, class _Alloc, class _InputIterator> map(_InputIterator, _InputIterator, const _Compare&, const _Alloc&)-> std::map<_Key, _Tp, _Compare, _Alloc>'
  302 |         map(_InputIterator __first, _InputIterator __last,
      |         ^~~
/usr/include/c++/14/bits/stl_map.h:302:9: note:   candidate expects 3 arguments, 0 provided
/usr/include/c++/14/bits/stl_map.h:285:9: note: candidate: 'template<class _Key, class _Tp, class _Compare, class _Alloc, class _InputIterator> map(_InputIterator, _InputIterator)-> std::map<_Key, _Tp, _Compare, _Alloc>'
  285 |         map(_InputIterator __first, _InputIterator __last)
      |         ^~~
/usr/include/c++/14/bits/stl_map.h:285:9: note:   candidate expects 2 arguments, 0 provided
/usr/include/c++/14/bits/stl_map.h:268:9: note: candidate: 'template<class _Key, class _Tp, class _Compare, class _Alloc, class _InputIterator> map(_InputIterator, _InputIterator, const _Alloc&)-> std::map<_Key, _Tp, _Compare, _Alloc>'
  268 |         map(_InputIterator __first, _InputIterator __last,
      |         ^~~
/usr/include/c++/14/bits/stl_map.h:268:9: note:   candidate expects 3 arguments, 0 provided
/usr/include/c++/14/bits/stl_map.h:262:7: note: candidate: 'template<class _Key, class _Tp, class _Compare, class _Alloc> map(std::initializer_list<std::pair<const _Key, _Val> >, const _Alloc&)-> std::map<_Key, _Tp, _Compare, _Alloc>'
  262 |       map(initializer_list<value_type> __l, const allocator_type& __a)
      |       ^~~
/usr/include/c++/14/bits/stl_map.h:262:7: note:   candidate expects 2 arguments, 0 provided
/usr/include/c++/14/bits/stl_map.h:256:7: note: candidate: 'template<class _Key, class _Tp, class _Compare, class _Alloc> map(std::map<_Key, _Tp, _Compare, _Allocator>&&, std::__type_identity_t<_Alloc>&)-> std::map<_Key, _Tp, _Compare, _Alloc>'
  256 |       map(map&& __m, const __type_identity_t<allocator_type>& __a)
      |       ^~~
/usr/include/c++/14/bits/stl_map.h:256:7: note:   candidate expects 2 arguments, 0 provided
/usr/include/c++/14/bits/stl_map.h:252:7: note: candidate: 'template<class _Key, class _Tp, class _Compare, class _Alloc> map(const std::map<_Key, _Tp, _Compare, _Allocator>&, std::__type_identity_t<_Alloc>&)-> std::map<_Key, _Tp, _Compare, _Alloc>'
  252 |       map(const map& __m, const __type_identity_t<allocator_type>& __a)
      |       ^~~
/usr/include/c++/14/bits/stl_map.h:252:7: note:   candidate expects 2 arguments, 0 provided
/usr/include/c++/14/bits/stl_map.h:248:7: note: candidate: 'template<class _Key, class _Tp, class _Compare, class _Alloc> map(const _Alloc&)-> std::map<_Key, _Tp, _Compare, _Alloc>'
  248 |       map(const allocator_type& __a)
      |       ^~~
/usr/include/c++/14/bits/stl_map.h:248:7: note:   candidate expects 1 argument, 0 provided
/usr/include/c++/14/bits/stl_map.h:240:7: note: candidate: 'template<class _Key, class _Tp, class _Compare, class _Alloc> map(std::initializer_list<std::pair<const _Key, _Val> >, const _Compare&, const _Alloc&)-> std::map<_Key, _Tp, _Compare, _Alloc>'
  240 |       map(initializer_list<value_type> __l,
      |       ^~~
/usr/include/c++/14/bits/stl_map.h:240:7: note:   candidate expects 1 argument, 0 provided
/usr/include/c++/14/bits/stl_map.h:227:7: note: candidate: 'template<class _Key, class _Tp, class _Compare, class _Alloc> map(std::map<_Key, _Tp, _Compare, _Allocator>&&)-> std::map<_Key, _Tp, _Compare, _Alloc>'
  227 |       map(map&&) = default;
      |       ^~~
/usr/include/c++/14/bits/stl_map.h:227:7: note:   candidate expects 1 argument, 0 provided
/usr/include/c++/14/bits/stl_map.h:219:7: note: candidate: 'template<class _Key, class _Tp, class _Compare, class _Alloc> map(const std::map<_Key, _Tp, _Compare, _Allocator>&)-> std::map<_Key, _Tp, _Compare, _Alloc>'
  219 |       map(const map&) = default;
      |       ^~~
/usr/include/c++/14/bits/stl_map.h:219:7: note:   candidate expects 1 argument, 0 provided
/usr/include/c++/14/bits/stl_map.h:206:7: note: candidate: 'template<class _Key, class _Tp, class _Compare, class _Alloc> map(const _Compare&, const _Alloc&)-> std::map<_Key, _Tp, _Compare, _Alloc>'
  206 |       map(const _Compare& __comp,
      |       ^~~
/usr/include/c++/14/bits/stl_map.h:206:7: note:   candidate expects 1 argument, 0 provided
/usr/include/c++/14/bits/stl_map.h:197:7: note: candidate: 'template<class _Key, class _Tp, class _Compare, class _Alloc> map()-> std::map<_Key, _Tp, _Compare, _Alloc>'
  197 |       map() = default;
      |       ^~~
/usr/include/c++/14/bits/stl_map.h:197:7: note:   template argument deduction/substitution failed:
a.cc:26:5: note:   couldn't deduce template parameter '_Key'
   26 | map m;
      |     ^
/usr/include/c++/14/bits/stl_map.h:102:11: note: candidate: 'template<class _Key, class _Tp, class _Compare, class _Alloc> map(std::map<_Key, _Tp, _Compare, _Alloc>)-> std::map<_Key, _Tp, _Compare, _Alloc>'
  102 |     class map
      |           ^~~
/usr/include/c++/14/bits/stl_map.h:102:11: note:   candidate expects 1 argument, 0 provided
/usr/include/c++/14/bits/stl_map.h:1495:5: note: candidate: 'template<class _Key, class _Tp, class _Allocator, class> std::map(initializer_list<pair<_T1, _T2> >, _Allocator)-> map<_Key, _Tp, less<_Key>, _Allocator>'
 1495 |     map(initializer_list<pair<_Key, _Tp>>, _Allocator)
      |     ^~~
/usr/include/c++/14/bits/stl_map.h:1495:5: note:   candidate expects 2 arguments, 0 provided
/usr/include/c++/14/bits/stl_map.h:1489:5: note: candidate: 'template<class _InputIterator, class _Allocator, class, class> std::map(_InputIterator, _InputIterator, _Allocator)-> map<typename remove_const<typename iterator_traits< <template-parameter-1-1> >::value_type::first_type>::type, typename iterator_traits< <template-parameter-1-1> >::value_type::second_type, less<typename remove_const<typename iterator_traits< <template-parameter-1-1> >::value_type::first_type>::type>, _Allocator>'
 1489 |     map(_InputIterator, _InputIterator, _Allocator)
      |     ^~~
/usr/include/c++/14/bits/stl_map.h:1489:5: note:   candidate expects 3 arguments, 0 provided
/usr/include/c++/14/bits/stl_map.h:1482:5: note: candidate: 'template<class _Key, class _Tp, class _Compare, class _Allocator, class, class> std::map(initializer_list<pair<_T1, _T2> >, _Compare, _Allocator)-> map<_Key, _Tp, _Compare, _Allocator>'
 1482 |     map(initializer_list<pair<_Key, _Tp>>,
      |     ^~~
/usr/include/c++/14/bits/stl_map.h:1482:5: note:   candidate expects 1 argument, 0 provided
/usr/include/c++/14/bits/stl_map.h:1473:5: note: candidate: 'template<class _InputIterator, class _Compare, class _Allocator, class, class, class> std::map(_InputIterator, _InputIterator, _Compare, _Allocator)-> map<typename remove_const<typename iterator_traits< <template-parameter-1-1> >::value_type::first_type>::type, typename iterator_traits< <template-parameter-1-1> >::value_type::second_type, _Compare, _Allocator>'
 1473 |     map(_InputIterator, _InputIterator,
      |     ^~~
/usr/include/c++/14/bits/stl_map.h:1473:5: note:   candidate expects 2 arguments, 0 provided