Language: C++

#include <bits/stdc++.h>
using namespace std;
long long ans = 0;
const int MAXN = 3e5+9;
long long row[MAXN], col[MAXN];
int R, C, M;
void func() {
	for (int i = 0; i < max(R, C); ++i) {
		if(i < R && i < C) {
			ans = max(ans, row[i] + col[i] - 1);
		}
		if(i < R){
			ans = max(ans, row[i]);
		}
		if(i < C){
			ans = max(ans, col[i]);
		}
	}
}

int main() {
	//freopen("input.txt", "r", stdin);

	cin >> R >> C >> M;
	// string s[R+5];
	// for (int i = 0; i < R; ++i) {
	// 	cin >> s[i];
	// }
	priority_queue<int> Q;
	for (int i = 0; i < M; ++i) {
		int r, c;
		cin >> r >> c;
		--r;
		--c;
		++row[r];
		++col[c];
		Q.push(row[r] + col[c] - 1);
		Q.push(row[r]);
		Q.push(col[c]);
	}

	// for (int i = 0; i < R; ++i) {
	// 	for (int j = 0; j < C; ++j){
	// 		ans = max(ans, row[i] + col[j] - 1);
	// 	}
	// }
	sort(row, row + R, greater<int>());
	sort(col, col + C, greater<int>());
	func();

	sort(row, row + R, greater<int>());
	sort(col, col + C);
	func();

	sort(row, row + R);
	sort(col, col + C, greater<int>());
	func();

	sort(row, row + R);
	sort(col, col + C);
	func();

	while((int)Q.size() > 0) {
		ans = max(ans, Q.top());
		Q.pop();
	}
	cout << ans << '\n';
	return 0;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:64:26: error: no matching function for call to 'max(long long int&, const __gnu_cxx::__alloc_traits<std::allocator<int>, int>::value_type&)'
   64 |                 ans = max(ans, Q.top());
      |                       ~~~^~~~~~~~~~~~~~
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:64:26: note:   deduced conflicting types for parameter 'const _Tp' ('long long int' and '__gnu_cxx::__alloc_traits<std::allocator<int>, int>::value_type' {aka 'int'})
   64 |                 ans = max(ans, Q.top());
      |                       ~~~^~~~~~~~~~~~~~
/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:64:26: note:   mismatched types 'std::initializer_list<_Tp>' and 'long long int'
   64 |                 ans = max(ans, Q.top());
      |                       ~~~^~~~~~~~~~~~~~