Language: C++

#include <bits/stdc++.h>
const long long MOD = 1000000007;
const int INF = INT_MAX / 2;
const long double PI = 3.1415926;
using namespace std;
#define FOR(i, r, n) for(int i=(ll)(r); i<(ll)(n); i++) 
#define REP(i, n) FOR(i, (0), n)
#define ALL(r) r.begin(), r.end()
#define ll long long int
typedef vector<ll> vc;
typedef vector<string> vcs;
typedef vector<pair<ll, ll>> vcp;
typedef vector<tuple<ll, ll, ll>> vct;
//vector<vector<ll>> vv(n, vector<ll>(n));

typedef int Weight;
struct Edge
{
	int from, to; Weight cost;
	bool operator < (const Edge& e) const { return cost < e.cost; }
	bool operator >(const Edge& e) const { return cost > e.cost; }
};
typedef vector<Edge> Edges;
typedef vector<Edges> Graph;
void add_edge(Graph &g, int from, int to, Weight cost)
{
	g[from].push_back(Edge{ from, to, cost });
}

int main()
{
	ll w, h, n;
	cin >> w >> h >> n;
	ll l = 0, r = w, d = 0, u = h;
	while (n--) {
		ll a, b, c;
		cin >> a >> b >> c;
		if (c == 1) l = max(a, l);
		else if (c == 2) r = min(a, r);
		else if (c == 3) d = max(b, d);
		else u = min(b, u);
	}
	cout << max(0, (r - l)*(u - d)) << endl;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:43:20: error: no matching function for call to 'max(int, long long int)'
   43 |         cout << max(0, (r - l)*(u - d)) << endl;
      |                 ~~~^~~~~~~~~~~~~~~~~~~~
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:43:20: note:   deduced conflicting types for parameter 'const _Tp' ('int' and 'long long int')
   43 |         cout << max(0, (r - l)*(u - d)) << endl;
      |                 ~~~^~~~~~~~~~~~~~~~~~~~
/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:43:20: note:   mismatched types 'std::initializer_list<_Tp>' and 'int'
   43 |         cout << max(0, (r - l)*(u - d)) << endl;
      |                 ~~~^~~~~~~~~~~~~~~~~~~~