Language: C++

#include<bits/stdc++.h>
#define range(i,a,b) for(int i = (a); i < (b); i++)
#define rep(i,b) for(int i = 0; i < (b); i++)
#define all(a) (a).begin(), (a).end()
#define show(x)  cerr << #x << " = " << (x) << endl;
#define int long long
using namespace std;

template <typename X, typename T>
auto vectors(X x, T a) {
	return vector<T>(x, a);
}

template <typename X, typename Y, typename Z, typename... Zs>
auto vectors(X x, Y y, Z z, Zs... zs) {
	auto cont = vectors(y, z, zs...);
	return vector<decltype(cont)>(x, cont);
}

template<typename T>
ostream& operator << (ostream& os, vector<T>& v){
	rep(i,v.size()){ os << v[i] << (i == v.size() - 1 ? "" : " "); } return os;
}
template<typename T>
istream& operator >> (istream& is, vector<T>& v){
	for(T& x: v){ is >> x; } return is;
}

void solve(){
	int n;
	cin >> n;

	vector<tuple<int, int, int>> t(n);
	rep(i,n){
		int a, b;
		cin >> a >> b;
		t[i] = make_tuple(a + b, a, b);
	}
	sort(all(t));

	int ans = 0;
	rep(i,n){
		if(i % 2) ans -= get<2>(t[i]);
		else  ans += get<1>(t[i]);
	}

	cout << ans << endl;
}

signed main(){
	solve();
	return 0;
	int n;
	cin >> n;

	vector<pair<int, int>> d(n);
	priority_queue<pair<int,int>> l, r;
	rep(i,n){
		int a, b;
		cin >> a >> b;
		d[i] = make_tuple(a - b,i);
		l.emplace(a,i);
		r.emplace(b,i);
	}
	sort(all(d));

	vector<bool> used(n, false);
	int ans = 0;
	int top = 0, bot = n - 1;
	rep(i,n){
		while(used[top]) top++;
		while(used[bot]) bot++;

		if(n % 2){

		}else{
			if(d[top] == d[bot]){
				while(true){
					int num, idx;
					tie(num, idx) = l.top(); l.pop();
					if(used[idx]) continue;
					used[idx] = true;
					ans += num;
					break;
				}
			}else{
			}
		}
	}
}


Compiler output:
a.cc: In function 'int main()':
a.cc:61:42: error: no match for 'operator=' (operand types are '__gnu_cxx::__alloc_traits<std::allocator<std::pair<long long int, long long int> >, std::pair<long long int, long long int> >::value_type' {aka 'std::pair<long long int, long long int>'} and 'std::tuple<long long int, long long int>')
   61 |                 d[i] = make_tuple(a - b,i);
      |                                          ^
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,
                 from a.cc:1:
/usr/include/c++/14/bits/stl_pair.h:946:9: note: candidate: 'template<class _U1, class _U2> typename std::enable_if<std::__and_<std::is_assignable<_T1&, const _U1&>, std::is_assignable<_T2&, const _U2&> >::value, std::pair<_T1, _T2>&>::type std::pair<_T1, _T2>::operator=(const std::pair<_U1, _U2>&) [with _U2 = _U1; _T1 = long long int; _T2 = long long int]'
  946 |         operator=(const pair<_U1, _U2>& __p)
      |         ^~~~~~~~
/usr/include/c++/14/bits/stl_pair.h:946:9: note:   template argument deduction/substitution failed:
a.cc:61:42: note:   'std::tuple<long long int, long long int>' is not derived from 'const std::pair<_T1, _T2>'
   61 |                 d[i] = make_tuple(a - b,i);
      |                                          ^
/usr/include/c++/14/bits/stl_pair.h:957:9: note: candidate: 'template<class _U1, class _U2> typename std::enable_if<std::__and_<std::is_assignable<_T1&, _U1&&>, std::is_assignable<_T2&, _U2&&> >::value, std::pair<_T1, _T2>&>::type std::pair<_T1, _T2>::operator=(std::pair<_U1, _U2>&&) [with _U2 = _U1; _T1 = long long int; _T2 = long long int]'
  957 |         operator=(pair<_U1, _U2>&& __p)
      |         ^~~~~~~~
/usr/include/c++/14/bits/stl_pair.h:957:9: note:   template argument deduction/substitution failed:
a.cc:61:42: note:   'std::tuple<long long int, long long int>' is not derived from 'std::pair<_T1, _T2>'
   61 |                 d[i] = make_tuple(a - b,i);
      |                                          ^
/usr/include/c++/14/bits/stl_pair.h:921:7: note: candidate: 'std::pair<_T1, _T2>& std::pair<_T1, _T2>::operator=(std::__conditional_t<((bool)std::__and_<std::is_copy_assignable<_T1>, std::is_copy_assignable<_T2> >::value), const std::pair<_T1, _T2>&, const std::__nonesuch&>) [with _T1 = long long int; _T2 = long long int; std::__conditional_t<((bool)std::__and_<std::is_copy_assignable<_T1>, std::is_copy_assignable<_T2> >::value), const std::pair<_T1, _T2>&, const std::__nonesuch&> = const std::pair<long long int, long long int>&]'
  921 |       operator=(__conditional_t<__and_<is_copy_assignable<_T1>,
      |       ^~~~~~~~
/usr/include/c++/14/bits/stl_pair.h:923:65: note:   no known conversion for argument 1 from 'std::tuple<long long int, long long int>' to 'std::__conditional_t<true, const std::pair<long long int, long long int>&, const std::__nonesuch&>' {aka 'const std::pair<long long int, long long int>&'}
  921 |       operator=(__conditional_t<__and_<is_copy_assignable<_T1>,
      |                 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~  
  922 |                                        is_copy_assignable<_T2>>::value,
      |                                        ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  923 |                                 const pair&, const __nonesuch&> __p)
      |                                 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~
/usr/include/c++/14/bits/stl_pair.h:931:7: note: candidate: 'std::pair<_T1, _T2>& std::pair<_T1, _T2>::operator=(std::__conditional_t<((bool)std::__and_<std::is_move_assignable<_Tp>, std::is_move_assignable<_T2> >::value), std::pair<_T1, _T2>&&, std::__nonesuch&&>) [with _T1 = long long int; _T2 = long long int; std::__conditional_t<((bool)std::__and_<std::is_move_assignable<_Tp>, std::is_move_assignable<_T2> >::value), std::pair<_T1, _T2>&&, std::__nonesuch&&> = std::pair<long long int, long long int>&&]'
  931 |       operator=(__conditional_t<__and_<is_move_assignable<_T1>,
      |       ^~~~~~~~
/usr/include/c++/14/bits/stl_pair.h:933:55: note:   no known conversion for argument 1 from 'std::tuple<long long int, long long int>' to 'std::__conditional_t<true, std::pair<long long int, long long int>&&, std::__nonesuch&&>' {aka 'std::pair<long long int, long long int>&&'}
  931 |       operator=(__conditional_t<__and_<is_move_assignable<_T1>,
      |                 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  932 |                                        is_move_assignable<_T2>>::value,
      |                                        ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  933 |                                 pair&&, __nonesuch&&> __p)
      |                                 ~~~~~~~~~~~~~~~~~~~~~~^~~