Language: C++

#include <bits/stdc++.h>

using namespace std;

#define int long long

int32_t main() {
   ios_base::sync_with_stdio(false);
   int N;
   cin >> N;
   vector<pair<int, int>> A(N);
   for (int i = 0; i < N; ++i) {
      cin >> A[i].first >> A[i].second;
      A[i].second = -A[i].second;
   }
   int ans = 0;
   sort(A.begin(), A.end());
   vector<pair<int, int>> B;
   vector<pair<int, int>> C;
   for (int i = 0; i < N; ++i) {
      A[i].second = -A[i].second;
      while (B.size() && B.back().second >= A[i].second) {
         C.emplace_back(B.back());
         B.pop_back();
      }
      B.emplace_back(A[i]);
   }
   for (int i = 0; i + 1 < B.size(); ++i) {
      int leftVal = max(0, B[0].second - B[i].first + 1);
      int rightVal = max(0, B[i + 1].second - B.back().first + 1);
      ans = max(ans, leftVal + rightVal);
   }
   int leftVal = max(0, B[0].second - B.back().first + 1);
   int rightVal = 0;
   for (auto p : C) {
      rightVal = max(rightVal, p.second - p.first + 1);
   }
   ans = max(ans, leftVal + rightVal);
   cout << ans << "\n";
   return 0;
}


Compiler output:
a.cc: In function 'int32_t main()':
a.cc:29:24: error: no matching function for call to 'max(int, long long int)'
   29 |       int leftVal = max(0, B[0].second - B[i].first + 1);
      |                     ~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
In file included 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_algobase.h:257:5: note: candidate: 'template<class _Tp> constexpr const _Tp& std::max(const _Tp&, const _Tp&)'
  257 |     max(const _Tp& __a, const _Tp& __b)
      |     ^~~
/usr/include/c++/14/bits/stl_algobase.h:257:5: note:   template argument deduction/substitution failed:
a.cc:29:24: note:   deduced conflicting types for parameter 'const _Tp' ('int' and 'long long int')
   29 |       int leftVal = max(0, B[0].second - B[i].first + 1);
      |                     ~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/14/bits/stl_algobase.h:303:5: note: candidate: 'template<class _Tp, class _Compare> constexpr const _Tp& std::max(const _Tp&, const _Tp&, _Compare)'
  303 |     max(const _Tp& __a, const _Tp& __b, _Compare __comp)
      |     ^~~
/usr/include/c++/14/bits/stl_algobase.h:303:5: note:   candidate expects 3 arguments, 2 provided
In file included from /usr/include/c++/14/algorithm:61:
/usr/include/c++/14/bits/stl_algo.h:5706:5: note: candidate: 'template<class _Tp> constexpr _Tp std::max(initializer_list<_Tp>)'
 5706 |     max(initializer_list<_Tp> __l)
      |     ^~~
/usr/include/c++/14/bits/stl_algo.h:5706:5: note:   candidate expects 1 argument, 2 provided
/usr/include/c++/14/bits/stl_algo.h:5716:5: note: candidate: 'template<class _Tp, class _Compare> constexpr _Tp std::max(initializer_list<_Tp>, _Compare)'
 5716 |     max(initializer_list<_Tp> __l, _Compare __comp)
      |     ^~~
/usr/include/c++/14/bits/stl_algo.h:5716:5: note:   template argument deduction/substitution failed:
a.cc:29:24: note:   mismatched types 'std::initializer_list<_Tp>' and 'int'
   29 |       int leftVal = max(0, B[0].second - B[i].first + 1);
      |                     ~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
a.cc:30:25: error: no matching function for call to 'max(int, long long int)'
   30 |       int rightVal = max(0, B[i + 1].second - B.back().first + 1);
      |                      ~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/14/bits/stl_algobase.h:257:5: note: candidate: 'template<class _Tp> constexpr const _Tp& std::max(const _Tp&, const _Tp&)'
  257 |     max(const _Tp& __a, const _Tp& __b)
      |     ^~~
/usr/include/c++/14/bits/stl_algobase.h:257:5: note:   template argument deduction/substitution failed:
a.cc:30:25: note:   deduced conflicting types for parameter 'const _Tp' ('int' and 'long long int')
   30 |       int rightVal = max(0, B[i + 1].second - B.back().first + 1);
      |                      ~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/14/bits/stl_algobase.h:303:5: note: candidate: 'template<class _Tp, class _Compare> constexpr const _Tp& std::max(const _Tp&, const _Tp&, _Compare)'
  303 |     max(const _Tp& __a, const _Tp& __b, _Compare __comp)
      |     ^~~
/usr/include/c++/14/bits/stl_algobase.h:303:5: note:   candidate expects 3 arguments, 2 provided
/usr/include/c++/14/bits/stl_algo.h:5706:5: note: candidate: 'template<class _Tp> constexpr _Tp std::max(initializer_list<_Tp>)'
 5706 |     max(initializer_list<_Tp> __l)
      |     ^~~
/usr/include/c++/14/bits/stl_algo.h:5706:5: note:   candidate expects 1 argument, 2 provided
/usr/include/c++/14/bits/stl_algo.h:5716:5: note: candidate: 'template<class _Tp, class _Compare> constexpr _Tp std::max(initializer_list<_Tp>, _Compare)'
 5716 |     max(initializer_list<_Tp> __l, _Compare __comp)
      |     ^~~
/usr/include/c++/14/bits/stl_algo.h:5716:5: note:   template argument deduction/substitution failed:
a.cc:30:25: note:   mismatched types 'std::initializer_list<_Tp>' and 'int'
   30 |       int rightVal = max(0, B[i + 1].second - B.back().first + 1);
      |                      ~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
a.cc:33:21: error: no matching function for call to 'max(int, long long int)'
   33 |    int leftVal = max(0, B[0].second - B.back().first + 1);
      |                  ~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/14/bits/stl_algobase.h:257:5: note: candidate: 'template<class _Tp> constexpr const _Tp& std::max(const _Tp&, const _Tp&)'
  257 |     max(const _Tp& __a, const _Tp& __b)
      |     ^~~
/usr/include/c++/14/bits/stl_algobase.h:257:5: note:   template argument deduction/substitution failed:
a.cc:33:21: note:   deduced conflicting types for parameter 'const _Tp' ('int' and 'long long int')
   33 |    int leftVal = max(0, B[0].second - B.back().first + 1);
      |                  ~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/14/bits/stl_algobase.h:303:5: note: candidate: 'template<class _Tp, class _Compare> constexpr const _Tp& std::max(const _Tp&, const _Tp&, _Compare)'
  303 |     max(const _Tp& __a, const _Tp& __b, _Compare __comp)
      |     ^~~
/usr/include/c++/14/bits/stl_algobase.h:303:5: note:   candidate expects 3 arguments, 2 provided
/usr/include/c++/14/bits/stl_algo.h:5706:5: note: candidate: 'template<class _Tp> constexpr _Tp std::max(initializer_list<_Tp>)'
 5706 |     max(initializer_list<_Tp> __l)
      |     ^~~
/usr/include/c++/14/bits/stl_algo.h:5706:5: note:   candidate expects 1 argument, 2 provided
/usr/include/c++/14/bits/stl_algo.h:5716:5: note: candidate: 'template<class _Tp, class _Compare> constexpr _Tp std::max(initializer_list<_Tp>, _Compare)'
 5716 |     max(initializer_list<_Tp> __l, _Compare __comp)
      |     ^~~
/usr/include/c++/14/bits/stl_algo.h:5716:5: note:   template argument deduction/substitution failed:
a.cc:33:21: note:   mismatched types 'std::initializer_list<_Tp>' and 'int'
   33 |    int leftVal = max(0, B[0].second - B.back().first + 1);
      |                  ~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~